meta-yocto-bsp: beaglebone: Add the u-boot boot config file for the wic image

(From meta-yocto rev: 800fc3ea87add6a7205ecfa3b088701ed635082f)

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-yocto-bsp/conf/machine/beaglebone-yocto.conf

@@ -37,4 +37,4 @@ UBOOT_LOADADDRESS = "0x80008000"
 
 MACHINE_FEATURES = "usbgadget usbhost vfat alsa"
 
-IMAGE_BOOT_FILES ?= "u-boot.${UBOOT_SUFFIX} MLO"
+IMAGE_BOOT_FILES ?= "u-boot.${UBOOT_SUFFIX} MLO zImage am335x-bone.dtb am335x-boneblack.dtb am335x-bonegreen.dtb"

meta-yocto-bsp/wic/beaglebone-yocto.wks

@@ -2,5 +2,5 @@
 # long-description: Creates a partitioned SD card image for Beaglebone.
 # Boot files are located in the first vfat partition.
 
-part /boot --source bootimg-partition --ondisk mmcblk0 --fstype=vfat --label boot --active --align 4 --size 16
+part /boot --source bootimg-partition --ondisk mmcblk0 --fstype=vfat --label boot --active --align 4 --size 16 --sourceparams="loader=u-boot"
 part / --source rootfs --ondisk mmcblk --fstype=ext4 --label root --align 4