Improve start-up timer for GeMM (floating-point):

 - Pass M,N,K at runtime as kernel parameters
 - Add a guard macro to compile only kernel of interest
 - Move reshpaing kernels to gemm_utils.cl
 - Remove the fallback reshaping kernel with Y-Padding support

Resolves: COMPMID-4888
Signed-off-by: Ramy Elgammal <ramy.elgammal@arm.com>
Change-Id: Ida3851326f0b77e410633271de9ecca106e37931
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/6662
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Gian Marco Iodice <gianmarco.iodice@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/SConscript b/SConscript
index 6420f31..6198445 100644
--- a/SConscript
+++ b/SConscript
@@ -310,6 +310,7 @@
                        'src/core/CL/cl_kernels/common/floor.cl',
                        'src/core/CL/cl_kernels/common/gather.cl',
                        'src/core/CL/cl_kernels/common/gemm.cl',
+                       'src/core/CL/cl_kernels/common/gemm_utils.cl',
                        'src/core/CL/cl_kernels/common/experimental/gemm_fused_post_ops/act_eltwise_op_act/gemm_mm_native.cl',
                        'src/core/CL/cl_kernels/common/experimental/gemm_fused_post_ops/act_eltwise_op_act/gemm_mm_reshaped.cl',
                        'src/core/CL/cl_kernels/common/experimental/gemm_fused_post_ops/act_eltwise_op_act/gemm_mm_reshaped_only_rhs.cl',