cpu/cc2538: added linkerscript for cc2538sf53
boards: added support for OpenMote
examples: blacklisted openmote for riot_and_cpp
Merge pull request #1864 from haukepetersen/add_board_openmote

boards: added support for OpenMote
doc: add doxygen predefines for periph headers
Merge pull request #1873 from LudwigOrtmann/doxygen-periph

doxygen: add predefines for periph headers