TQM85xx: adapt for new flash types

Old TQM85xx boards had 'M' type Spansion Flashes from the S29GLxxxM
series while new boards have 'N' type Flashes from the S29GLxxxN
series, which have bigger sectors: 2 x 128 instead of 2 x 64 KB.

We now change the configuration to the new flash types for all
boards; this also works on old boards - we just waste two flash
sectors for the environment which could be smaller there.

Signed-off-by: Wolfgang Denk <wd@denx.de>