cmake: Add PACKAGECONFIG option for debugger support

cmake: Add PACKAGECONFIG option for debugger support

Starting from CMake version 2.27 support for interactive debugging of CMake
scripts and configurations was added. However, by default the `nativesdk-cmake`
is compiled with debugger support turned off.

This change adds debugger support for cmake

(From OE-Core rev: 8acfca456c3502f0d097ba01a2d08f83fb75ab60)

Signed-off-by: Nikhil R <nikhilr5@kpit.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>