[source] kernel/spi-gpio-custom: drop Build/Prepare rule in favor of default one

[LEDE Commits]

blogic pushed a commit to source.git, branch master:
https://git.lede-project.org/9168abe8b5f43d2afa16e9c45f768a9165dfbd0d

commit 9168abe8b5f43d2afa16e9c45f768a9165dfbd0d
Author: Alexandru Ardelean <ardeleanalex at gmail.com>
AuthorDate: Thu Oct 6 09:38:42 2016 +0300

    kernel/spi-gpio-custom: drop Build/Prepare rule in favor of default one
    
    Signed-off-by: Alexandru Ardelean <ardeleanalex at gmail.com>
---
 package/kernel/spi-gpio-custom/Makefile | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/package/kernel/spi-gpio-custom/Makefile b/package/kernel/spi-gpio-custom/Makefile
index 3282f06..e6d692d 100644
--- a/package/kernel/spi-gpio-custom/Makefile
+++ b/package/kernel/spi-gpio-custom/Makefile
@@ -39,11 +39,6 @@ MAKE_OPTS:= \
 	EXTRA_CFLAGS="$(EXTRA_CFLAGS)" \
 	$(EXTRA_KCONFIG)
 
-define Build/Prepare
-	mkdir -p $(PKG_BUILD_DIR)
-	$(CP) ./src/* $(PKG_BUILD_DIR)/
-endef
-
 define Build/Compile
 	$(MAKE) -C "$(LINUX_DIR)" \
 		$(MAKE_OPTS) \