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/configs/pico-hobbit-imx6ul_defconfig b/configs/pico-hobbit-imx6ul_defconfig
index 88a07c0..0894111 100644
--- a/configs/pico-hobbit-imx6ul_defconfig
+++ b/configs/pico-hobbit-imx6ul_defconfig
@@ -16,7 +16,7 @@
 CONFIG_DEFAULT_DEVICE_TREE="imx6ul-pico-hobbit"
 CONFIG_SPL_TEXT_BASE=0x00908000
 CONFIG_SPL_MMC=y
-CONFIG_SPL_SERIAL_SUPPORT=y
+CONFIG_SPL_SERIAL=y
 CONFIG_SPL=y
 CONFIG_SPL_LIBDISK_SUPPORT=y
 CONFIG_DISTRO_DEFAULTS=y