configs: arm64: ls1012afrdm Enable CONFIG_BLK

With DM_USB enabled, enable CONFIG_BLK to remove this
compile warning for ls1012afrdm based targets:

===================== WARNING ======================
This board does not use CONFIG_DM_USB. Please update
the board to use CONFIG_DM_USB before the v2019.07 release.
Failure to update by the deadline may result in board removal.
See doc/driver-model/migration.rst for more info.
====================================================

Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/configs/ls1012afrdm_qspi_defconfig b/configs/ls1012afrdm_qspi_defconfig
index 11d0cee..1e60148 100644
--- a/configs/ls1012afrdm_qspi_defconfig
+++ b/configs/ls1012afrdm_qspi_defconfig
@@ -5,6 +5,7 @@
 CONFIG_ENV_SECT_SIZE=0x40000
 CONFIG_ENV_OFFSET=0x300000
 CONFIG_DM_GPIO=y
+CONFIG_BLK=y
 CONFIG_FSL_LS_PPA=y
 CONFIG_QSPI_AHB_INIT=y
 CONFIG_NR_DRAM_BANKS=2