x-wic.inc: Default partition extra args to avoid expansion issues

When not defined, bitbake will not expand the variables and wic will be
passed unrecognized arguments. Here is an example:

unrecognized arguments: ${WIC_ROOTA_PARTITION_EXTRA_ARGS}

Fixes #69

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>

meta-ohos-core/conf/distro/include/x-wic.inc

@@ -16,6 +16,15 @@ DEVICEDATA_PARTITION_SIZE ?= "8M"
 SYSDATA_PARTITION_SIZE ?= "512M"
 APPDATA_PARTITION_SIZE ?= "1G"
 
+#
+# Use this to include extra wic configuration per partition
+#
+WIC_ROOTA_PARTITION_EXTRA_ARGS ??= ""
+WIC_ROOTB_PARTITION_EXTRA_ARGS ??= ""
+WIC_DEVICEDATA_PARTITION_EXTRA_ARGS ??= ""
+WIC_SYSDATA_PARTITION_EXTRA_ARGS ??= ""
+WIC_APPDATA_PARTITION_EXTRA_ARGS ??= ""
+
 WIC_ROOTA_PARTITION      ?= "part / --source rootfs --use-uuid --fstype=ext4 --label x-sys-a    --mkfs-extraopts '-T default' --align 4096 --fixed-size ${ROOTA_PARTITION_SIZE}      ${WIC_ROOTA_PARTITION_EXTRA_ARGS}"
 WIC_ROOTB_PARTITION      ?= "part                              --fstype=ext4 --label x-sys-b    --mkfs-extraopts '-T default' --align 4096 --fixed-size ${ROOTB_PARTITION_SIZE}      ${WIC_ROOTB_PARTITION_EXTRA_ARGS}"
 WIC_DEVICEDATA_PARTITION ?= "part                              --fstype=ext4 --label x-dev-data --mkfs-extraopts '-T default' --align 4096 --fixed-size ${DEVICEDATA_PARTITION_SIZE} ${WIC_DEVICEDATA_PARTITION_EXTRA_ARGS}"