Bazel and CMake optional fp16 support

Resolves ONCPUML-1274

Signed-off-by: David Svantesson <david.svantesson@arm.com>
Change-Id: I1d189596cfce5be87a18c8065d683700b3c9960f
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/9745
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: SiCong Li <sicong.li@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>
diff --git a/.bazelrc b/.bazelrc
index d6a5e62..1dbbedc 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -38,3 +38,4 @@
 build --flag_alias=cppthreads=//:cppthreads
 build --flag_alias=enable_bf16_validation=//:enable_bf16_validation
 build --flag_alias=enable_sve_validation=//:enable_sve_validation
+build --flag_alias=arch=//:arch