ARMv8/sec_firmware: relocated and renamed the config FSL_PPA_ARMV8_PSCI

Moved the config FSL_PPA_ARMV8_PSCI from fsl-layerscape's Kconfig to
Kconfig under armv8 and renamed it to SEC_FIRMWARE_ARMV8_PSCI.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/arch/arm/cpu/armv8/Kconfig b/arch/arm/cpu/armv8/Kconfig
index 7ef9c2f..0b3d98e 100644
--- a/arch/arm/cpu/armv8/Kconfig
+++ b/arch/arm/cpu/armv8/Kconfig
@@ -63,6 +63,14 @@
 	help
 	  Say Y here to support this framework in SPL phase.
 
+config SEC_FIRMWARE_ARMV8_PSCI
+	bool "PSCI implementation in secure monitor firmware"
+	depends on ARMV8_SEC_FIRMWARE_SUPPORT || SPL_ARMV8_SEC_FIRMWARE_SUPPORT
+	help
+	  This config enables the ARMv8 PSCI implementation in secure monitor
+	  firmware. This is a private PSCI implementation and different from
+	  those implemented under the common ARMv8 PSCI framework.
+
 config ARMV8_SEC_FIRMWARE_ERET_ADDR_REVERT
 	bool "ARMv8 secure monitor firmware ERET address byteorder swap"
 	depends on ARMV8_SEC_FIRMWARE_SUPPORT || SPL_ARMV8_SEC_FIRMWARE_SUPPORT