drivers: input: atmel: allow forced calibrations

Calibrations are sometimes necessary, allow calibrations even
when calibration_disabled is set to 1.

Also, pressing volume up and volume down at the same time will
always start calibrations.
latona: change usb device descriptor
drivers: leds: add helper to make LEDs blink
drivers: input: twl4030_keypad: touchscreen calibration feedback

When a touchscreen calibration is forced pressing both the volume
keys, LEDs will blink twice.
latona: force the UART path to PDA