meta-nuvoton: Add build wic image support

We add wks file and relative config for build wic image. Now user can
build wic image by include phosphor-mmc.inc. And set WKS_RWFS_SIZE,
WKS_RWFS_SIZE to adjust eMMC parition size instead of create new wks
file for each board.

Change-Id: I1ed342658d791fd9011bd31ea6db36d4362d120b
Signed-off-by: Brian Ma <chma0@nuvoton.com>
diff --git a/meta-nuvoton/conf/machine/include/nuvoton.inc b/meta-nuvoton/conf/machine/include/nuvoton.inc
index 9662af9..2673e3b 100644
--- a/meta-nuvoton/conf/machine/include/nuvoton.inc
+++ b/meta-nuvoton/conf/machine/include/nuvoton.inc
@@ -3,5 +3,14 @@
 PREFERRED_PROVIDER_u-boot ?= "u-boot-nuvoton"
 PREFERRED_PROVIDER_u-boot-fw-utils ?= "u-boot-fw-utils-nuvoton"
 
+WKS_FILE ?= "emmc-nuvoton.wks.in"
+WKS_FILE_DEPENDS ?= " \
+    virtual/kernel \
+"
+WKS_RWFS_SIZE ??= "256M"
+WKS_ROFS_SIZE ??= "256M"
+IMAGE_BOOT_FILES ?= "fitImage-${INITRAMFS_IMAGE}-${MACHINE}-${MACHINE};fitImage"
+IMAGE_FSTYPES:remove:df-phosphor-mmc = "mtd-static mtd-static-tar mtd-static-alltar"
+
 MACHINEOVERRIDES .= ":nuvoton"
 MACHINE_EXTRA_RRECOMMENDS += "udev-nuvoton-mtd-partitions"