boot/uboot/uboot.mk: add pmufw.elf support

This patch adds support for zynqmp pmufw.elf files.
It will allow buildroot to use pmufw.elf binaries directly
from the Xilinx git repository built by petalinux in
addition to still supporting pmufw.bin binaries built
by the zynqmp-pmufw-builder.

https://github.com/Xilinx/ubuntu-firmware/tree/v2022.1_22.04_1/xlnx-firmware

Signed-off-by: Neal Frager <neal.frager@amd.com>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

boot/uboot/uboot.mk

@@ -391,9 +391,12 @@ UBOOT_ZYNQMP_PMUFW_PATH = $(UBOOT_DL_DIR)/$(notdir $(UBOOT_ZYNQMP_PMUFW))
 else ifneq ($(UBOOT_ZYNQMP_PMUFW),)
 UBOOT_ZYNQMP_PMUFW_PATH = $(shell readlink -f $(UBOOT_ZYNQMP_PMUFW))
 endif
+UBOOT_ZYNQMP_PMUFW_BASENAME = $(basename $(UBOOT_ZYNQMP_PMUFW_PATH))
 
 define UBOOT_ZYNQMP_KCONFIG_PMUFW
-	$(call KCONFIG_SET_OPT,CONFIG_PMUFW_INIT_FILE,"$(UBOOT_ZYNQMP_PMUFW_PATH)")
+	$(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")
 endef
 
 UBOOT_ZYNQMP_PM_CFG = $(call qstrip,$(BR2_TARGET_UBOOT_ZYNQMP_PM_CFG))