plat: marvell: armada: a3k: Do not modify $(WTMI_IMG)

$(WTMI_IMG) is used only by $(MAKE) subprocess in $(DOIMAGEPATH) directory.
So calling truncate on $(WTMI_IMG) after $(MAKE) in $(DOIMAGEPATH) has no
effect and can just damage input file for future usage. Therefore remove
this truncate call.
Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I9925c54c5d3d10eadc19825c5565ad4598a739a7

plat/marvell/armada/a3k/common/a3700_common.mk

@@ -128,7 +128,6 @@ $(DOIMAGETOOL):
 mrvl_flash: ${BUILD_PLAT}/${BOOT_IMAGE} ${DOIMAGETOOL}
 	$(if $(value MV_DDR_PATH),,$(error "Platform '${PLAT}' for target '$@' requires MV_DDR_PATH. Please set MV_DDR_PATH to point to the right directory"))
 	${Q}${MAKE} --no-print-directory -C ${DOIMAGEPATH} WTMI_IMG=$(WTMI_IMG) MV_DDR_PATH=$(MV_DDR_PATH)
-	$(shell truncate -s %4 $(WTMI_IMG))
 	@echo
 	@echo "Building uart images"
 	$(TIMBUILD) $(TIMBLDUARTARGS)