serial: Rename SERIAL_SUPPORT to SERIAL

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/mach-omap2/am33xx/Kconfig b/arch/arm/mach-omap2/am33xx/Kconfig
index b29ecba..1402376 100644
--- a/arch/arm/mach-omap2/am33xx/Kconfig
+++ b/arch/arm/mach-omap2/am33xx/Kconfig
@@ -51,7 +51,7 @@
 	imply SPL_OF_LIBFDT
 	imply SPL_POWER
 	imply SPL_SEPARATE_BSS
-	imply SPL_SERIAL_SUPPORT
+	imply SPL_SERIAL
 	imply SPL_SYS_MALLOC_SIMPLE
 	imply SPL_WATCHDOG
 	imply SPL_YMODEM_SUPPORT
@@ -233,7 +233,7 @@
 	imply SPL_MMC
 	imply SPL_NAND_SUPPORT
 	imply SPL_POWER
-	imply SPL_SERIAL_SUPPORT
+	imply SPL_SERIAL
 	imply SPL_WATCHDOG
 	imply SPL_YMODEM_SUPPORT
 	help