Undo update bf16_conversion extension

Author: aidan.belton

sycl/doc/extensions/experimental/SYCL_EXT_ONEAPI_BF16_CONVERSION.asciidoc renamed to sycl/doc/extensions/experimental/SYCL_EXT_INTEL_BF16_CONVERSION.asciidoc

@@ -1,4 +1,4 @@
-= SYCL_ONEAPI_bfloat16
+= SYCL_INTEL_bf16_conversion
 
 :source-highlighter: coderay
 :coderay-linenums-mode: table
@@ -73,7 +73,7 @@ command (e.g. from `parallel_for`).
 This extension provides a feature-test macro as described in the core SYCL
 specification section 6.3.3 "Feature test macros". Therefore, an implementation
 supporting this extension must predefine the macro
-`SYCL_EXT_ONEAPI_BFLOAT16_CONVERSION` to one of the values defined in the table
+`SYCL_EXT_INTEL_BF16_CONVERSION` to one of the values defined in the table
 below. Applications can test for the existence of this macro to determine if
 the implementation supports this feature, or applications can test the macro’s
  value to determine which of the extension’s APIs the implementation supports.
@@ -91,18 +91,18 @@ the implementation supports this feature, or applications can test the macro’s
 namespace sycl {
 enum class aspect {
   ...
-  ext_oneapi_bfloat16
+  ext_intel_bf16_conversion
 }
 }
 ----
 
-If a SYCL device has the `ext_oneapi_bfloat16` aspect, then it natively
+If a SYCL device has the `ext_intel_bf16_conversion` aspect, then it natively
 supports conversion of values of `float` type to `bfloat16` and back.
 
 If the device doesn't have the aspect, objects of `bfloat16` class must not be
 used in the device code.
 
-**NOTE**: The `ext_oneapi_bfloat16` aspect is not yet supported.  The
+**NOTE**: The `ext_intel_bf16_conversion` aspect is not yet supported.  The
 `bfloat16` class is currently supported only on Xe HP GPU.
 
 == New `bfloat16` class
@@ -115,7 +115,7 @@ mode.
 ----
 namespace sycl {
 namespace ext {
-namespace oneapi {
+namespace intel {
 namespace experimental {
 
 class bfloat16 {
@@ -171,7 +171,7 @@ public:
 };
 
 } // namespace experimental
-} // namespace oneapi
+} // namespace intel
 } // namespace ext
 } // namespace sycl
 ----
@@ -277,9 +277,9 @@ OP is `==, !=, <, >, <=, >=`
 [source]
 ----
 #include <sycl/sycl.hpp>
-#include <sycl/ext/oneapi/experimental/bfloat16.hpp>
+#include <sycl/ext/intel/experimental/bfloat16.hpp>
 
-using sycl::ext::oneapi::experimental::bfloat16;
+using sycl::ext::intel::experimental::bfloat16;
 
 bfloat16 operator+(const bfloat16 &lhs, const bfloat16 &rhs) {
   return static_cast<float>(lhs) + static_cast<float>(rhs);
@@ -304,7 +304,7 @@ int main (int argc, char *argv[]) {
   sycl::queue deviceQueue{dev};
   sycl::buffer<float, 1> buf {data, sycl::range<1> {3}};
 
-  if (dev.has(sycl::aspect::ext_oneapi_bfloat16)) {
+  if (dev.has(sycl::aspect::ext_intel_bf16_conversion)) {
     deviceQueue.submit ([&] (sycl::handler& cgh) {
       auto numbers = buf.get_access<sycl::access::mode::read_write> (cgh);
       cgh.single_task<class simple_kernel> ([=] () {