ARM: OMAP1: osk5912: Mistral eeprom support

List the 4 Kbit I2C EEPROM included on the Mistral board.

Also add a comment about the hardware workaround needed to
properly support the WAKE button.  More info at

  http://elinux.org/OSK_Mistral_wakeup_button_mod

Still no support for the (optional) camera sensor.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>