ARM: PSCI: Support PSCI v0.2

Enhance the PSCI DT editing code to allow setting a PSCI v0.2 compatible
value in the DT. The CONFIG_ option is added to the whitelist to match the
existing PSCI_1_0 option. While not adding new options to Kconfig isn't
ideal, I figure it's better to keep related options together.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/arch/arm/lib/psci-dt.c b/arch/arm/lib/psci-dt.c
index 825fe1e..348df89 100644
--- a/arch/arm/lib/psci-dt.c
+++ b/arch/arm/lib/psci-dt.c
@@ -67,6 +67,8 @@
 	psci_ver = sec_firmware_support_psci_version();
 #elif defined(CONFIG_ARMV7_PSCI_1_0) || defined(CONFIG_ARMV8_PSCI)
 	psci_ver = ARM_PSCI_VER_1_0;
+#elif defined(CONFIG_ARMV7_PSCI_0_2)
+	psci_ver = ARM_PSCI_VER_0_2;
 #endif
 	if (psci_ver >= ARM_PSCI_VER_1_0) {
 		tmp = fdt_setprop_string(fdt, nodeoff,