native.bbclass: deltask package_qa

native.bbclass: deltask package_qa

The native recipe doesn't need package_qa, and it has a race issue with
do_unpack which requires the clean dir of ${S}, then causes error:

NOTE: recipe opkg-utils-native-0.1.8+gitAUTOINC+eae0d8fa44-r0: task do_package_qa: Failed
ERROR: Task 283 (virtual:native:/path/to/opkg-utils_git.bb, do_package_qa) failed with exit code '1'

(From OE-Core rev: 6ad0979a6064755fd6d86b568bd3cbbcdd3d4e37)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>