Rename GPIO_SUPPORT to GPIO

Rename these options so that CONFIG_IS_ENABLED can be used with them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 1fd39a0..2b7b625 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1019,7 +1019,7 @@
 	imply FIT
 	imply OF_LIBFDT_OVERLAY
 	imply PRE_CONSOLE_BUFFER
-	imply SPL_GPIO_SUPPORT
+	imply SPL_GPIO
 	imply SPL_LIBCOMMON_SUPPORT
 	imply SPL_LIBGENERIC_SUPPORT
 	imply SPL_MMC_SUPPORT if MMC