image.bbclass: inherit image_types_uboot when needed
Fixed:
MACHINE = "qemuarm"
IMAGE_FSTYPES += "ext3.bz2.u-boot"
[snip]
No IMAGE_CMD defined for IMAGE_FSTYPES entry 'ext3.bz2.u-boot' - possibly invalid type name or missing support class
[snip]
This is because image_types_uboot is not inherited, inherit it when
needed will fix the problem.
Signed-off-by: Robert Yang <liezhi.yang@windriver.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
