pia335x: completely remove MMC WD and CD pin configurations

Signed-off-by: Björn Krombholz <b.krombholz@pironex.de>
pia335x: make u-boot for MMI and E2 boards not depend on #defines

- It's easier to handle a single u-boot for similar boards.
  Use the EEPROM detection for configuration selection.
- The special first boot initialization version still need to be spearated,
  as there is no easy way to detect the board type with an empty EEPROM.

Signed-off-by: Björn Krombholz <b.krombholz@pironex.de>
pia335x: print detected board even if DEBUG is disabled

Signed-off-by: Björn Krombholz <b.krombholz@pironex.de>