kbuild: add %asm-generic to no-dot-config-targets

asm-generic and uapi-asm-generic do not depend on the kernel
configuration.  In fact, uapi-asm-generic is the prerequisite of
headers_{install,check}, hence it should not require the .config file.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NRichard Weinberger <richard@nod.at>

Makefile

@@ -224,7 +224,7 @@ clean-targets := %clean mrproper cleandocs
 no-dot-config-targets := $(clean-targets) \
 			 cscope gtags TAGS tags help% %docs check% coccicheck \
 			 $(version_h) headers_% archheaders archscripts \
-			 kernelversion %src-pkg
+			 %asm-generic kernelversion %src-pkg
 
 config-targets := 0
 mixed-targets  := 0