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/common/spl/Kconfig b/common/spl/Kconfig
index 15ddb0d..87f65ea 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -1108,7 +1108,7 @@
 	  Sector on the SATA disk to load U-Boot from, when the SATA disk is being
 	  used in raw mode. Units: SATA disk sectors (1 sector = 512 bytes).
 
-config SPL_SERIAL_SUPPORT
+config SPL_SERIAL
 	bool "Support serial"
 	select SPL_PRINTF
 	select SPL_STRTO
@@ -1258,7 +1258,7 @@
 
 config SPL_USB_SDP_SUPPORT
 	bool "Support SDP (Serial Download Protocol)"
-	depends on SPL_SERIAL_SUPPORT
+	depends on SPL_SERIAL
 	help
 	  Enable Serial Download Protocol (SDP) device support in SPL. This
 	  allows to download images into memory and execute (jump to) them
@@ -1284,7 +1284,7 @@
 
 config SPL_YMODEM_SUPPORT
 	bool "Support loading using Ymodem"
-	depends on SPL_SERIAL_SUPPORT
+	depends on SPL_SERIAL
 	help
 	  While loading from serial is slow it can be a useful backup when
 	  there is no other option. The Ymodem protocol provides a reliable
@@ -1571,12 +1571,12 @@
 	  needed. This enables the drivers in drivers/rtc as part of an TPL
 	  build.
 
-config TPL_SERIAL_SUPPORT
+config TPL_SERIAL
 	bool "Support serial"
 	select TPL_PRINTF
 	select TPL_STRTO
 	help
-	  Enable support for serial in TPL. See SPL_SERIAL_SUPPORT for
+	  Enable support for serial in TPL. See SPL_SERIAL for
 	  details.
 
 config TPL_SPI_FLASH_SUPPORT
@@ -1620,7 +1620,7 @@
 
 config TPL_YMODEM_SUPPORT
 	bool "Support loading using Ymodem"
-	depends on TPL_SERIAL_SUPPORT
+	depends on TPL_SERIAL
 	help
 	  While loading from serial is slow it can be a useful backup when
 	  there is no other option. The Ymodem protocol provides a reliable