MLK-21905 mx7ulp_evk: Change kernel DTB to EVKB board

The latest mx7ulp evk board is renamed to EVKB board and has dedicated
DTB files. Modify the kernel DTB names in u-boot to use the new DTB.

Signed-off-by: Ye Li <ye.li@nxp.com>
Acked-by: Peng Fan <peng.fan@nxp.com>
(cherry picked from commit 297a924ddaf456a5a175d9056c0bc45116cc49ce)
diff --git a/configs/mx7ulp_evk_m4boot_defconfig b/configs/mx7ulp_evk_m4boot_defconfig
index 24e34e1..6b1135c 100644
--- a/configs/mx7ulp_evk_m4boot_defconfig
+++ b/configs/mx7ulp_evk_m4boot_defconfig
@@ -3,7 +3,7 @@
 CONFIG_SYS_TEXT_BASE=0x67800000
 CONFIG_TARGET_MX7ULP_EVK=y
 CONFIG_NR_DRAM_BANKS=1
-CONFIG_DEFAULT_FDT_FILE="imx7ulp-evk"
+CONFIG_DEFAULT_FDT_FILE="imx7ulp-evkb"
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/mx7ulp_evk/imximage.cfg"
 CONFIG_BOUNCE_BUFFER=y
 CONFIG_BOARD_LATE_INIT=y