brcm2708-gpu-fw: move pkg build dir to kernel build dir to fix rebuild bugs after cleaning the kernel tree

Backport of r48732

patches/openwrt/0049-brcm2708-gpu-fw-move-pkg-build-dir-to-kernel-build-dir-to-fix-rebuild-bugs-after-cleaning-the-kernel-tree.patch

@@ -0,0 +1,19 @@
+From: Matthias Schiffer <mschiffer@universe-factory.net>
+Date: Sun, 28 Feb 2016 02:29:56 +0100
+Subject: brcm2708-gpu-fw: move pkg build dir to kernel build dir to fix rebuild bugs after cleaning the kernel tree
+
+Backport of r48732
+
+diff --git a/package/kernel/brcm2708-gpu-fw/Makefile b/package/kernel/brcm2708-gpu-fw/Makefile
+index eee85e0..286984b 100644
+--- a/package/kernel/brcm2708-gpu-fw/Makefile
++++ b/package/kernel/brcm2708-gpu-fw/Makefile
+@@ -16,7 +16,7 @@ PKG_SOURCE:=$(PKG_REV).tar.gz
+ PKG_SOURCE_URL:=https://github.com/Hexxeh/rpi-firmware/archive/
+ PKG_MD5SUM:=f5683c1dcb255714942f7c9fd61b3a0a
+ 
+-PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)/rpi-firmware-$(PKG_REV)
++PKG_BUILD_DIR:=$(KERNEL_BUILD_DIR)/$(PKG_NAME)/rpi-firmware-$(PKG_REV)
+ 
+ include $(INCLUDE_DIR)/package.mk
+