Add SME2 implementation of softmax for FP16

In addition to the softmax kernel, this patch fixes minor issues in the fp32 implementation.

Resolves: COMPMID-6920

Change-Id: Ibbd9f0af5f2a93fba0e92d72ba437279c34149d3
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/11402
Benchmark: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Viet-Hoa Do <viet-hoa.do@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/filelist.json b/filelist.json
index f6e8547..497da8e 100644
--- a/filelist.json
+++ b/filelist.json
@@ -2238,7 +2238,8 @@
           },
           "sve2":{
             "common" :["src/cpu/kernels/softmax/generic/sve2/impl.cpp"],
-            "fp32" :["src/cpu/kernels/softmax/generic/sme2/fp32.cpp"]
+            "fp32" :["src/cpu/kernels/softmax/generic/sme2/fp32.cpp"],
+            "fp16" :["src/cpu/kernels/softmax/generic/sme2/fp16.cpp"]
           }
         }
       },