Remove preprocess xplat build

Summary:
Fix the error
```
BUILD FAILED
Error running analysis for `fbsource//xplat/executorch/backends/qualcomm:preprocess (cfg:linux-x86_64-fbcode-platform010-clang15-no-san#5d1c5fc41fddc9ad)`

Caused by:
    0: Error in configured node dependency, dependency chain follows (-> indicates depends on, ^ indicates same configuration as previous):
              fbsource//xplat/executorch/backends/qualcomm:preprocess (cfg:linux-x86_64-fbcode-platform010-clang15-no-san#5d1c5fc41fddc9ad)
           -> fbsource//xplat/executorch/backends/qualcomm/passes:passes (^)

    1: looking up unconfigured target node `fbsource//xplat/executorch/backends/qualcomm/passes:passes`
    2: Error loading targets in package `fbsource//xplat/executorch/backends/qualcomm/passes` for target `fbsource//xplat/executorch/backends/qualcomm/passes:passes`
    3: package `fbsource//xplat/executorch/backends/qualcomm/passes:` does not exist
           missing `BUCK` file (also missing alternatives `BUCK.v2`, `BUCK`)
```
In https://www.internalfb.com/sandcastle/workflow/941252322124876986/artifact/actionlog.941252322206237690.stdout.1?selectedLines=622-633-1-77

Differential Revision: D63587929

Author: cccclai

backends/qualcomm/TARGETS

@@ -1,5 +1,18 @@
+load("@fbsource//xplat/executorch/build:runtime_wrapper.bzl", "runtime")
 load(":targets.bzl", "define_common_targets")
 
 oncall("executorch")
 
 define_common_targets()
+
+runtime.python_library(
+    name = "preprocess",
+    srcs = ["qnn_preprocess.py"],
+    visibility = [
+        "//executorch/backends/qualcomm/...",
+        "@EXECUTORCH_CLIENTS",
+    ],
+    deps = [
+        "//executorch/backends/qualcomm/passes:passes",
+    ],
+)

backends/qualcomm/passes/TARGETS

@@ -1,5 +1,18 @@
-load(":targets.bzl", "define_common_targets")
+load("@fbsource//xplat/executorch/build:runtime_wrapper.bzl", "runtime")
 
 oncall("executorch")
 
-define_common_targets()
+runtime.python_library(
+    name = "passes",
+    srcs = glob([
+        "*.py",
+    ]),
+    visibility = [
+        "@EXECUTORCH_CLIENTS",
+    ],
+    deps = [
+        "//executorch/backends/transforms:addmm_mm_to_linear",
+        "//executorch/exir/backend:backend_details",
+        "//executorch/exir/backend:compile_spec_schema",
+    ],
+)

backends/qualcomm/passes/targets.bzl

@@ -2,10 +2,8 @@ load(
     "@fbsource//tools/build_defs:default_platform_defs.bzl",
     "ANDROID",
 )
-load("@fbcode_macros//build_defs:python_library.bzl", "python_library")
 load("@fbsource//xplat/executorch/build:runtime_wrapper.bzl", "runtime")
 
-
 # Construct the input and output file names. All input and output files rely on scalar_type file.
 SCHEMA_NAME = "schema"
 
@@ -56,6 +54,7 @@ def define_common_targets():
         [OUTPUT_SCHEMA_HEADER],
         OUTPUT_SCHEMA_HEADER,
     )
+
     # Header-only library target with the generate executorch program schema header.
     runtime.cxx_library(
         name = "schema",
@@ -77,7 +76,6 @@ def define_common_targets():
         platforms = [ANDROID],
     )
 
-
     runtime.cxx_library(
         name = "qnn_executorch_backend",
         srcs = [],
@@ -94,15 +92,3 @@ def define_common_targets():
             ":schema",
         ],
     )
-    
-    runtime.python_library(
-        name = "preprocess",
-        srcs = ["qnn_preprocess.py"],
-        deps = [
-            "//executorch/backends/qualcomm/passes:passes",
-        ],
-        visibility = [
-            "//executorch/backends/qualcomm/...",
-            "@EXECUTORCH_CLIENTS",
-        ],
-    )