Add platform device-id table in order to identify the controller and
determine its configuration.

The currently used configuration parameters are:

have_alt_pixclock
 - SOC uses an alternate pixel-clock calculation formula (at91sam9g45
   non-ES)

have_hozval
 - SOC has a HOZVAL field in LCDFRMCFG which is used to determine the
   linesize for STN displays (at91sam9261, at921sam9g10 and at32ap)

have_intensity_bit
 - SOC uses IBGR:555 rather than BGR:565 16-bit pixel layout
   (at91sam9261, at91sam9263 and at91sam9rl)

This allows us to remove all the remaining uses of cpu_is macros from
the driver.

Tested on at91sam9263 and at91sam9g45, compile-tested for other
AT91-SOCs, and untested for AVR32.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>