Convert CONFIG_FSL_DCU_FB to Kconfig

Rename CONFIG_FSL_DCU_FB to CONFIG_VIDEO_FSL_DCU_FB
and convert it to Kconfig.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Reviewed-by: Stefan Agner <stefan.agner@toradex.com>
Reviewed-by: Alison Wang <alison.wang@nxp.com>
diff --git a/configs/ls1021atwr_sdcard_ifc_SECURE_BOOT_defconfig b/configs/ls1021atwr_sdcard_ifc_SECURE_BOOT_defconfig
index 783787a..bd00170 100644
--- a/configs/ls1021atwr_sdcard_ifc_SECURE_BOOT_defconfig
+++ b/configs/ls1021atwr_sdcard_ifc_SECURE_BOOT_defconfig
@@ -57,5 +57,6 @@
 CONFIG_USB_XHCI_DWC3=y
 CONFIG_USB_STORAGE=y
 # CONFIG_VIDEO_SW_CURSOR is not set
+CONFIG_VIDEO_FSL_DCU_FB=y
 CONFIG_RSA=y
 CONFIG_SPL_RSA=y