uboot-lantiq: remove duplicate define

Signed-off-by: Luka Perkov <luka@openwrt.org>

SVN-Revision: 40779

package/boot/uboot-lantiq/Makefile

@@ -19,8 +19,6 @@ PKG_SOURCE_URL:= \
 PKG_MD5SUM:=a076a044b64371edc52f7e562b13f6b2
 PKG_TARGETS:=bin
 
-PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_NAME)-$(BUILD_VARIANT)/$(PKG_NAME)-$(PKG_VERSION)
-
 PKG_BUILD_PARALLEL:=1
 
 FIRMWARE_LANTIQ_SOURCE:=$(TOPDIR)/target/linux/lantiq/files/firmware/lantiq