tegra: image: remove image padding

Commit "build: Remove TARGET_IMAGES_PAD option" has removed this config
option so remove it from this target as well.

Signed-off-by: Petr Štetiar <ynezz@true.cz>

target/linux/tegra/image/Makefile

@@ -25,7 +25,6 @@ define Build/tegra-sdcard
 		-d $@-boot.scr \
 		$@.boot/boot.scr
 
-	PADDING="$(CONFIG_TARGET_IMAGES_PAD)" \
 	SIGNATURE="$(SIGNATURE)" \
 	$(SCRIPT_DIR)/gen_image_generic.sh \
 		$@ \