m68k: implemented a proper a_loadaddr_ref_cgpara instead of the disabled mess in the source, utilizing the PEA instruction

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@28075 3ad0048d-3df7-0310-abae-a5850022a9f2
m68k: cleaned ancient silly debug mess from a_loadaddr_ref_reg. no functional changes.

git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@28076 3ad0048d-3df7-0310-abae-a5850022a9f2