[ARM] 3078/1: lubbock platform updates, mostly mmc detection

Patch from David Brownell

Lubbock updates:

  * Provide an address for the SMC91x chip that doesn't generate
    a boot-time warning (matching the EEPROM).

  * Update MMC support to (a) detect card insert/remove, and
    (b) report the readonly switch setting for SD cards.

Previously, MMC/SD cards had to be present at boot time else they
couldn't be detected.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>