arm64: use psci reset on snapdragon

This actually works on snapdragon.. not sure why we weren't using it.
Fixes reboot/poweroff when using UEFI.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Alexander Graf <agraf@suse.de>

arch/arm/cpu/armv8/Kconfig

@@ -92,7 +92,7 @@ config PSCI_RESET
 		   !TARGET_LS1043ARDB && !TARGET_LS1043AQDS && \
 		   !TARGET_LS1046ARDB && !TARGET_LS1046AQDS && \
 		   !TARGET_LS2081ARDB && \
-		   !ARCH_UNIPHIER && !ARCH_SNAPDRAGON && !TARGET_S32V234EVB
+		   !ARCH_UNIPHIER && !TARGET_S32V234EVB
 	help
 	  Most armv8 systems have PSCI support enabled in EL3, either through
 	  ARM Trusted Firmware or other firmware.