meta-quanta: olympus-nuvoton: change machine configuration

1. specify uboot dtb
2. remove unsupported image type

Change-Id: Icac0161c309ab238885781732b84cb9f2b3bcd0f
Signed-off-by: Stanley Chu <yschu@nuvoton.com>
diff --git a/meta-olympus-nuvoton/conf/machine/olympus-nuvoton.conf b/meta-olympus-nuvoton/conf/machine/olympus-nuvoton.conf
index 77e0a32..7fadd1a 100644
--- a/meta-olympus-nuvoton/conf/machine/olympus-nuvoton.conf
+++ b/meta-olympus-nuvoton/conf/machine/olympus-nuvoton.conf
@@ -11,10 +11,10 @@
 FLASH_RWFS_OFFSET = "29696"
 
 UBOOT_MACHINE = "PolegRunBMC_defconfig"
+UBOOT_DEVICETREE = "nuvoton-npcm750-olympus"
 IGPS_MACHINE = "RunBMC"
 
 IMAGE_FSTYPES += " cpio.${INITRAMFS_CTYPE}.u-boot"
-IMAGE_FSTYPES += " mtd-ubi-tar"
 
 OBMC_MACHINE_FEATURES += "\
         obmc-phosphor-fan-mgmt \