boot/uboot: fix dependency on xilinx-prebuilt

When building with `make -j` and PER_PACKAGE_DIRECTORIES, a race
condition occurs between xilinx-prebuilt and u-boot, resulting in the
following error.

  objcopy -O binary -I elf32-little .../images/pmufw.elf .../images/pmufw.bin
  objcopy: '.../images/pmufw.elf': No such file

U-Boot registers a KCONFIG_FIXUP_CMD that uses the pmufw.elf from
xilinx-prebuilt. But KCONFIG_FIXUP_CMDS does not use the normal
DEPENDENCIES, so xilinx-prebuilt is not guaranteed to have run before
fixup.

Instead move the `objcopy` call out to a PRE_BUILD_HOOK so it will run
after xilinx-prebuilt has finished.

Signed-off-by: Brandon Maier <brandon.maier@collins.com>
Tested-by: Neal Frager <neal.frager@amd.com>
Reviewed-by: Neal Frager <neal.frager@amd.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

boot/uboot/uboot.mk

@@ -460,13 +460,17 @@ endif #ifneq ($(findstring ://,$(UBOOT_ZYNQMP_PMUFW)),)
 
 endif #BR2_TARGET_UBOOT_ZYNQMP_PMUFW_PREBUILT
 
-UBOOT_ZYNQMP_PMUFW_BASENAME = $(basename $(UBOOT_ZYNQMP_PMUFW_PATH))
-
+ifeq ($(suffix $(UBOOT_ZYNQMP_PMUFW_PATH)),.elf)
+UBOOT_ZYNQMP_PMUFW_PATH_FINAL = $(basename $(UBOOT_ZYNQMP_PMUFW_PATH)).bin
+define UBOOT_ZYNQMP_PMUFW_CONVERT
+	objcopy -O binary -I elf32-little $(UBOOT_ZYNQMP_PMUFW_PATH) $(UBOOT_ZYNQMP_PMUFW_PATH_FINAL)
+endef
+UBOOT_PRE_BUILD_HOOKS += UBOOT_ZYNQMP_PMUFW_CONVERT
+else
+UBOOT_ZYNQMP_PMUFW_PATH_FINAL = $(UBOOT_ZYNQMP_PMUFW_PATH)
+endif
 define UBOOT_ZYNQMP_KCONFIG_PMUFW
-	$(if $(filter %.elf,$(UBOOT_ZYNQMP_PMUFW_PATH)),
-		objcopy -O binary -I elf32-little $(UBOOT_ZYNQMP_PMUFW_BASENAME).elf $(UBOOT_ZYNQMP_PMUFW_BASENAME).bin
-		$(call KCONFIG_SET_OPT,CONFIG_PMUFW_INIT_FILE,"$(UBOOT_ZYNQMP_PMUFW_BASENAME).bin"),
-		$(call KCONFIG_SET_OPT,CONFIG_PMUFW_INIT_FILE,"$(UBOOT_ZYNQMP_PMUFW_PATH)"))
+	$(call KCONFIG_SET_OPT,CONFIG_PMUFW_INIT_FILE,"$(UBOOT_ZYNQMP_PMUFW_PATH_FINAL)")
 endef
 
 UBOOT_ZYNQMP_PM_CFG = $(call qstrip,$(BR2_TARGET_UBOOT_ZYNQMP_PM_CFG))