COMPMID-3152: Initial Bfloat16 support

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: Ie6959e37e13731c86b2ee29392a99a293450a1b4
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/2824
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>
diff --git a/SConstruct b/SConstruct
index 83b1409..0076a36 100644
--- a/SConstruct
+++ b/SConstruct
@@ -205,7 +205,7 @@
         env.Append(CXXFLAGS = ['-march=armv8-a'])
 
     if 'v8.6-a' in env['arch']:
-        env.Append(CXXFLAGS = ['-DV8P6'])
+        env.Append(CPPDEFINES = ['V8P6', 'ARM_COMPUTE_FORCE_BF16'])
 
 elif 'x86' in env['arch']:
     if env['estate'] == '32':