Create export_sp CMake function

Move the contents of environments/opteesp/ExportSp.cmake into the
export_sp function of tools/cmake/common/ExportSp.cmake. Change
existing deployments to use the export_sp function. This is a
preparation for having generic format SPs.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I0fe147327aa4f5a80eb6b6ab1c3e45bf3490dce9
9 files changed