kernel: prevent addition of scm marker to localversion

When building the kernel from a git repository, the kernel build appends
either a + or a short commit hash to localversion.
This behaviour can be prevented by passing the empty LOCALVERSION variable
to make.

Signed-off-by: Josua Mayer <josua.mayer97@gmail.com>

include/kernel-defaults.mk

@@ -33,6 +33,10 @@ ifdef CONFIG_USE_SPARSE
   KERNEL_MAKEOPTS += C=1 CHECK=$(STAGING_DIR_HOST)/bin/sparse
 endif
 
+ifneq ($(strip $(CONFIG_KERNEL_GIT_CLONE_URI)),"")
+ KERNEL_MAKEOPTS += LOCALVERSION=
+endif
+
 export HOST_EXTRACFLAGS=-I$(STAGING_DIR_HOST)/include
 
 # defined in quilt.mk