image.bbclass/populate_sdk_base.bbclass: shift position of sdk complementary install...

image.bbclass/populate_sdk_base.bbclass: shift position of sdk complementary install definition

The sdk complementary install operation was defined in image.bbclass,
but the sdk recipe (such as meta-toolchain.bb) didn't inherit this
bbclass but populate_sdk, and both of image and populate_sdk bbclass
inherited populate_sdk_base bbclass, so move the sdk complementary
install definition to populate_sdk_base bbclass fixed this issue.

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>