Enable ccache for kernel compile

Just needed to pass in ccache as a prefix to the CROSS_TARGET variable.

Signed-off-by: Martin Hicks <mort@bork.org>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

linux/linux.mk

@@ -23,7 +23,7 @@ LINUX26_MAKE_FLAGS = \
 	HOSTCFLAGS="$(HOSTCFLAGS)" \
 	ARCH=$(KERNEL_ARCH) \
 	INSTALL_MOD_PATH=$(TARGET_DIR) \
-	CROSS_COMPILE=$(TARGET_CROSS) \
+	CROSS_COMPILE="$(CCACHE) $(TARGET_CROSS)" \
 	LZMA="$(LZMA)"
 
 # Get the real Linux version, which tells us where kernel modules are