kbuild: do not update config for 'make kernelrelease'

'make kernelrelease' depends on CONFIG_LOCALVERSION(_AUTO), but
for the same reason as install targets, we do not want to update
the configuration just for printing the kernelrelease string.

This is likely to happen when you compiled the kernel with
CROSS_COMPILE, but forget to pass it to 'make kernelrelease'.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Makefile

@@ -225,7 +225,8 @@ no-dot-config-targets := $(clean-targets) \
 			 cscope gtags TAGS tags help% %docs check% coccicheck \
 			 $(version_h) headers_% archheaders archscripts \
 			 kernelversion %src-pkg
-no-sync-config-targets := $(no-dot-config-targets) install %install
+no-sync-config-targets := $(no-dot-config-targets) install %install \
+			   kernelrelease
 
 config-targets  := 0
 mixed-targets   := 0