arm64: zynqmp: probe firmware driver

Probe ZynqMP firmware driver on the board initialization phase and
ensure that firmware is in place to continue execution. The probing is
done on board_init so it can be used for both SPL and U-Boot proper.

Signed-off-by: Ibai Erkiaga <ibai.erkiaga-elorza@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0c41bc3..90bcc8d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1057,9 +1057,12 @@
 	select DM_SPI if SPI
 	select DM_SPI_FLASH if DM_SPI
 	select DM_USB if USB
+	select FIRMWARE
 	select OF_CONTROL
 	select SPL_BOARD_INIT if SPL
 	select SPL_CLK if SPL
+	select SPL_DM_MAILBOX if SPL
+	select SPL_FIRMWARE if SPL
 	select SPL_SEPARATE_BSS if SPL
 	select SUPPORT_SPL
 	select ZYNQMP_IPI