firmware: psci: introduce SPL_ARM_PSCI_FW

Introduce a new macro SPL_ARM_PSCI_FW

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Stefano Babic <sbabic@denx.de>
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index feaea81..7d8f161 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -1,6 +1,10 @@
 config FIRMWARE
 	bool "Enable Firmware driver support"
 
+config SPL_ARM_PSCI_FW
+	bool
+	select FIRMWARE
+
 config ARM_PSCI_FW
 	bool
 	select FIRMWARE