Rename SPL_POWER_SUPPORT to SPL_POWER

Rename this option so that CONFIG_IS_ENABLED can be used with it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/configs/k2g_evm_defconfig b/configs/k2g_evm_defconfig
index 01df882..b350349 100644
--- a/configs/k2g_evm_defconfig
+++ b/configs/k2g_evm_defconfig
@@ -26,7 +26,7 @@
 CONFIG_SPL_NAND_DRIVERS=y
 CONFIG_SPL_NAND_ECC=y
 CONFIG_SPL_NAND_BASE=y
-CONFIG_SPL_POWER_SUPPORT=y
+CONFIG_SPL_POWER=y
 CONFIG_SPL_SPI_LOAD=y
 CONFIG_CMD_MX_CYCLIC=y
 # CONFIG_CMD_FLASH is not set