kbuild: rpm-pkg: move source components to rpmbuild/SOURCES

Prepare to add more files to the source RPM.

Also, fix the build error when KCONFIG_CONFIG is set:
  error: Bad file: ./.config: No such file or directory

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index d0a0ba8e5a2e..dfff9f8d28e5 100644
--- a/Makefile
+++ b/Makefile
@@ -1605,7 +1605,7 @@ MRPROPER_FILES += include/config include/generated          \
 		  certs/signing_key.pem \
 		  certs/x509.genkey \
 		  vmlinux-gdb.py \
-		  *.spec \
+		  *.spec rpmbuild \
 		  rust/libmacros.so
 
 # clean - Delete most, but leave enough to build external modules