CI: Switch ppc64le debug build to RUST_OPT_LEVEL_0

To avoid stack overflow we need to increase the kernel stack size to
32K (THREAD_SHIFT = 15).

Signed-off-by: Michael Ellerman <[email protected]>

Author: mpe

.github/workflows/kernel-ppc64le-debug.config

@@ -356,7 +356,7 @@ CONFIG_ILLEGAL_POINTER_VALUE=0x5deadbeef0000000
 # CONFIG_PPC_4K_PAGES is not set
 CONFIG_PPC_64K_PAGES=y
 CONFIG_PPC_PAGE_SHIFT=16
-CONFIG_THREAD_SHIFT=14
+CONFIG_THREAD_SHIFT=15
 CONFIG_DATA_SHIFT=16
 CONFIG_FORCE_MAX_ZONEORDER=9
 # CONFIG_PPC_SUBPAGE_PROT is not set
@@ -1581,8 +1581,8 @@ CONFIG_RUNTIME_TESTING_MENU=y
 #
 CONFIG_RUST_DEBUG_ASSERTIONS=y
 CONFIG_RUST_OVERFLOW_CHECKS=y
-CONFIG_RUST_OPT_LEVEL_SIMILAR_AS_CHOSEN_FOR_C=y
-# CONFIG_RUST_OPT_LEVEL_0 is not set
+# CONFIG_RUST_OPT_LEVEL_SIMILAR_AS_CHOSEN_FOR_C is not set
+CONFIG_RUST_OPT_LEVEL_0=y
 # CONFIG_RUST_OPT_LEVEL_1 is not set
 # CONFIG_RUST_OPT_LEVEL_2 is not set
 # CONFIG_RUST_OPT_LEVEL_3 is not set