Convert CONFIG_PL011_SERIAL et al to Kconfig

This converts the following to Kconfig:
   CONFIG_PL011_SERIAL
   CONFIG_PL01X_SERIAL

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/lx2160aqds_tfa_defconfig b/configs/lx2160aqds_tfa_defconfig
index 98ad60a..ddcf681 100644
--- a/configs/lx2160aqds_tfa_defconfig
+++ b/configs/lx2160aqds_tfa_defconfig
@@ -89,6 +89,7 @@
 CONFIG_RTC_PCF2127=y
 CONFIG_DM_SCSI=y
 CONFIG_DM_SERIAL=y
+CONFIG_PL01X_SERIAL=y
 CONFIG_SPI=y
 CONFIG_DM_SPI=y
 CONFIG_FSL_DSPI=y