Remove unused CLGEMMMatrixVectorMultiplyKernel

Partially Resolves: COMPMID-3924

Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Change-Id: Ibc47bd5bf5203dbad8d0755608918fcb384053c3
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4633
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/docs/00_introduction.dox b/docs/00_introduction.dox
index 7fe73c4..bdfbdb8 100644
--- a/docs/00_introduction.dox
+++ b/docs/00_introduction.dox
@@ -88,6 +88,8 @@
 
 v21.02 Public major release
  - Upgraded C++ standard to C++14
+ - Removed kernels:
+   - NEGEMMMatrixVectorMultiplyKernel
 
 v20.11 Public major release
  - Various bug fixes.