image.bbclass: don't emit redundant IMAGE_CMD_xxx functions
IMAGE_CMD_xxx commands are always inlined within do_image_xxx.
When IMAGE_CMD_xxx is defined as a function (e.g. IMAGE_CMD_btrfs,
IMAGE_CMD_cpio, etc), a redundant copy of the function will be emitted
by default. Remove IMAGE_CMD_xxx 'func' flags to prevent that.
(From OE-Core rev:
118c1ca4d8d62162e87caf287f96d90707ee5903)
Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster@mvista.com>
