ARM: at91/dt: add peripherals to the at91sam9rlek board

This adds support for:
 - SPI
 - Dataflash
 - LCD
 - i2c
 - ADC
 - Touchscreen
 - USB gadget
 - PWM

Also it switches the ds1 and ds2 leds to PWM control.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>