[ARM] 4144/1: Fix for patch #4099/1 with CONFIG_I2C_PXA_SLAVE set

Switch the i2c-pxa driver to actually using the platform device information and let it handle the power i2c bus on pxa27x too. Original version of this patch didn't compile with CONFIG_I2C_PXA_SLAVE set.

Signed-off-by: G. Liakhovetski <gl@dsa-ac.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>