package/gcc: fix list of files of patch file to hash for ccache

When we build the list of patches to include to compute the hash for
ccache, a typo precented the special gcc-initial/ and gcc-final/
directories from a global patch dir to be included in the calculation.

Fix that by properly expanding the $(PKG) variable.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: He Chunhui <hchunhui@mail.ustc.edu.cn>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/gcc/gcc.mk

@@ -252,8 +252,8 @@ HOST_GCC_COMMON_CCACHE_HASH_FILES += $(DL_DIR)/$(GCC_SOURCE)
 HOST_GCC_COMMON_CCACHE_HASH_FILES += \
 	$(sort $(wildcard \
 		package/gcc/$(GCC_VERSION)/*.patch \
-		$(addsuffix /$((PKG)_RAWNAME)/$(GCC_VERSION)/*.patch,$(call qstrip,$(BR2_GLOBAL_PATCH_DIR))) \
-		$(addsuffix /$((PKG)_RAWNAME)/*.patch,$(call qstrip,$(BR2_GLOBAL_PATCH_DIR))) \
+		$(addsuffix /$($(PKG)_RAWNAME)/$(GCC_VERSION)/*.patch,$(call qstrip,$(BR2_GLOBAL_PATCH_DIR))) \
+		$(addsuffix /$($(PKG)_RAWNAME)/*.patch,$(call qstrip,$(BR2_GLOBAL_PATCH_DIR))) \
 		$(addsuffix /gcc/$(GCC_VERSION)/*.patch,$(call qstrip,$(BR2_GLOBAL_PATCH_DIR))) \
 		$(addsuffix /gcc/*.patch,$(call qstrip,$(BR2_GLOBAL_PATCH_DIR)))))
 ifeq ($(BR2_xtensa),y)