[source] kernel/gpio-button-hotplug: 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/a1236a30a05b0eeaf3b52ad73b21ec2b8e0fedc1

commit a1236a30a05b0eeaf3b52ad73b21ec2b8e0fedc1
Author: Alexandru Ardelean <ardeleanalex at gmail.com>
AuthorDate: Thu Oct 6 09:34:46 2016 +0300

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

diff --git a/package/kernel/gpio-button-hotplug/Makefile b/package/kernel/gpio-button-hotplug/Makefile
index b9a481a..a067adc 100644
--- a/package/kernel/gpio-button-hotplug/Makefile
+++ b/package/kernel/gpio-button-hotplug/Makefile
@@ -36,11 +36,6 @@ MAKE_OPTS:= \
 	CROSS_COMPILE="$(TARGET_CROSS)" \
 	SUBDIRS="$(PKG_BUILD_DIR)"
 
-define Build/Prepare
-	mkdir -p $(PKG_BUILD_DIR)
-	$(CP) ./src/* $(PKG_BUILD_DIR)/
-endef
-
 define Build/Compile
 	$(MAKE) -C "$(LINUX_DIR)" \
 		$(MAKE_OPTS) \