TQM8260: environment in flash instead EEPROM, baudrate 115k

Several customers have reported problems with the environment in
EEPROM, including corrupted content after board reset. Probably the
code to prevent I2C Enge Conditions is not working sufficiently.

We move the environment to flash now, which allows to have a backup
copy plus gives much faster boot times.

Also, change the default console initialization to 115200 bps as used
on most other boards.

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