Blackfin arch: noMMU CPLB lookup tables can be in L1 SRAM

 - unify duplicate page_size_table definitions
 - make sure it is placed alongside the other cplb switching code

Pointed-out-by: Michael McTernan <mmcternan@airvana.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>