meta/classes/testimage.bbclass: add testsdk task and enable functionality for it.
- add new testsdk task for meta-toolchain testing.
- enable the get_tests_list method to work with sdk tests.
- add default TEST_SUITES value for meta-toolchain package
NOTE: Original patch made by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Corneliu Stoicescu <corneliux.stoicescu@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
