package/gdb: use the Xtensa variables

... instead of re-computing them over-and-over-again.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gdb/gdb.mk

@@ -44,11 +44,9 @@ HOST_GDB_MAKE_OPTS += MAKEINFO=true
 HOST_GDB_INSTALL_OPTS += MAKEINFO=true install
 
 # Apply the Xtensa specific patches
-XTENSA_CORE_NAME = $(call qstrip, $(BR2_XTENSA_CORE_NAME))
-ifneq ($(XTENSA_CORE_NAME),)
+ifneq ($(ARCH_XTENSA_CORE_NAME),)
 define GDB_XTENSA_PRE_PATCH
-	tar xf $(BR2_XTENSA_OVERLAY_DIR)/xtensa_$(XTENSA_CORE_NAME).tar \
-		-C $(@D) --strip-components=1 gdb
+	tar xf $(ARCH_XTENSA_OVERLAY_TAR) -C $(@D) --strip-components=1 gdb
 endef
 GDB_PRE_PATCH_HOOKS += GDB_XTENSA_PRE_PATCH
 HOST_GDB_PRE_PATCH_HOOKS += GDB_XTENSA_PRE_PATCH