The omap3 and omap4/am33xx spi cores differ in the offset of the
registers in the address space. Instead of encoding this into the
resources use the platform_device_id mechanism. This is done in
preparation for devicetree probe support where the address space
is in the devicetree and can't be adjusted.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>