ARM: 6085/1: ux500: reorganize i2c devices

Move common i2c devices to devices.c and DB8500-specific I2C
devices to devices-db8500.c.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>