Convert CONFIG_SD_BOOT et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SD_BOOT
   CONFIG_SD_BOOT_QSPI

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ls1021aqds_sdcard_qspi_defconfig b/configs/ls1021aqds_sdcard_qspi_defconfig
index 082ef4c..a6411ad 100644
--- a/configs/ls1021aqds_sdcard_qspi_defconfig
+++ b/configs/ls1021aqds_sdcard_qspi_defconfig
@@ -26,11 +26,11 @@
 CONFIG_SYS_LOAD_ADDR=0x82000000
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
-CONFIG_SYS_EXTRA_OPTIONS="SD_BOOT,SD_BOOT_QSPI"
 CONFIG_RAMBOOT_PBL=y
 CONFIG_SYS_FSL_PBL_PBI="board/freescale/ls1021aqds/ls102xa_pbi.cfg"
 CONFIG_SYS_FSL_PBL_RCW="board/freescale/ls1021aqds/ls102xa_rcw_sd_qspi.cfg"
 CONFIG_SD_BOOT=y
+CONFIG_SD_BOOT_QSPI=y
 CONFIG_BOOTDELAY=3
 CONFIG_SILENT_CONSOLE=y
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y