[ARM] 4826/1: Orion: Register the RTC interrupt on the TS-209

The QNAP TS-209 has its RTC interrupt on GPIO 3. Setup this
as an interrupt and pass it to the i2c_board_info.

Signed-off-by: Byron Bradley <byron.bbradley@gmail.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>