powerpc: mpc85xx: Fix static TLB table for SDRAM

powerpc: mpc85xx: Fix static TLB table for SDRAM

Most predefined TLB tables don't have memory coherence bit set for
SDRAM. This wasn't an issue before invalidate_dcache_range() function
was enabled. Without the coherence bit, dcache invalidation doesn't
automatically flush the cache. The coherence bit is already set when
dynamic TLB table is used. For some boards with different SPL boot
method, or with legacy fixed setting, this bit needs to be set in
TLB files.

Signed-off-by: York Sun <york.sun@nxp.com>