wic: Add --compress-with command line option

Added -c/--compress-with command line option to 'wic create'
subcommand. This option is used to specify compressor
utility to compress the image produced by wic. gzip, bzip2 and
xz compressors are supported in this implementation.

(From OE-Core rev: 8425ef0a67aa5ca7b2dbf4c461004af555aa0c96)

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/image/help.py

@@ -152,6 +152,7 @@ SYNOPSIS
         [-e | --image-name] [-s, --skip-build-check] [-D, --debug]
         [-r, --rootfs-dir] [-b, --bootimg-dir]
         [-k, --kernel-dir] [-n, --native-sysroot] [-f, --build-rootfs]
+        [-c, --compress-with]
 
 DESCRIPTION
     This command creates an OpenEmbedded image based on the 'OE
@@ -218,6 +219,9 @@ DESCRIPTION
     The -o option can be used to place the image in a directory with a
     different name and location.
 
+    The -c option is used to specify compressor utility to compress
+    an image. gzip, bzip2 and xz compressors are supported.
+
     The set of properties available for a given image type can be
     listed using the 'wic list' command.
 """

scripts/wic

@@ -105,6 +105,9 @@ def wic_create_subcommand(args, usage_str):
     parser.add_option("-p", "--skip-build-check", dest="build_check",
                       action="store_false", default=True, help="skip the build check")
     parser.add_option("-f", "--build-rootfs", action="store_true", help="build rootfs")
+    parser.add_option("-c", "--compress-with", choices=("gzip", "bzip2", "xz"),
+                      dest='compressor',
+                      help="compress image with specified compressor")
     parser.add_option("-D", "--debug", dest="debug", action="store_true",
                       default=False, help="output debug information")