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/P2020RDB-PC_36BIT_NAND_defconfig b/configs/P2020RDB-PC_36BIT_NAND_defconfig
index 96ec9a8..b3373bc 100644
--- a/configs/P2020RDB-PC_36BIT_NAND_defconfig
+++ b/configs/P2020RDB-PC_36BIT_NAND_defconfig
@@ -5,7 +5,7 @@
 CONFIG_SYS_MALLOC_LEN=0x100000
 CONFIG_DEFAULT_DEVICE_TREE="p2020rdb-pc_36b"
 CONFIG_SPL_TEXT_BASE=0xFF800000
-CONFIG_SPL_SERIAL_SUPPORT=y
+CONFIG_SPL_SERIAL=y
 CONFIG_TPL_LIBCOMMON_SUPPORT=y
 CONFIG_TPL_LIBGENERIC_SUPPORT=y
 CONFIG_SPL=y
@@ -31,7 +31,7 @@
 CONFIG_TPL_I2C=y
 CONFIG_TPL_MPC8XXX_INIT_DDR_SUPPORT=y
 CONFIG_TPL_NAND_SUPPORT=y
-CONFIG_TPL_SERIAL_SUPPORT=y
+CONFIG_TPL_SERIAL=y
 CONFIG_HUSH_PARSER=y
 # CONFIG_AUTO_COMPLETE is not set
 CONFIG_CMD_IMLS=y