Update CPU kernel implementations and guard directives

Resolves COMPMID-6023

Change-Id: I868975d14c4f98af6716726feda22405a6a4c891
Signed-off-by: Michael Tyler <michael.tyler@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/9686
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Viet-Hoa Do <viet-hoa.do@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>
diff --git a/SConscript b/SConscript
index 72b6303..370486e 100644
--- a/SConscript
+++ b/SConscript
@@ -574,7 +574,8 @@
 
 if env['neon']:
     # build winograd/depthwise sources for either v7a / v8a
-    arm_compute_env.Append(CPPPATH = ["src/core/NEON/kernels/convolution/common/",
+    arm_compute_env.Append(CPPPATH = ["src/core/NEON/kernels/arm_gemm",
+                                      "src/core/NEON/kernels/convolution/common/",
                                       "src/core/NEON/kernels/convolution/winograd/",
                                       "src/core/NEON/kernels/arm_conv/depthwise/",
                                       "src/core/NEON/kernels/arm_conv/pooling/",