refact(twdog): move trusted wdog API to spm_common

Other tests cases need same API to enable/disable twdog,
so we need to move them to common place.

Signed-off-by: Nabil Kahlouche <nabil.kahlouche@arm.com>
Change-Id: Ie54cfdf44777000dda924bb1239b77182a3dced9
3 files changed