core-image*sdk: Add kernel-dev to sdk images

core-image*sdk: Add kernel-dev to sdk images

While sdk images already have dev-pkgs included, the kernel-dev package
is special and does not get installed. Add kernel-dev explicitly to the
*sdk image recipes.

Note: We have to be careful with "IMAGE_INSTALL +=" as it must appear
after "inherit core-image" which makes an "IMAGE_INSTALL ?=" assignment.

(From OE-Core rev: 337428316de3612a8e1efa70b3a4ba7cb6e058d2)

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
CC: Jessica Zhang <jessica.zhang@intel.com>
CC: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>