mvebu: config define i2c pxa slave
We are setting CONFIG_I2C_PXA is not set
If you do set pxa to y then you have issues if you do not have
CONFIG_I2C_PXA_SLAVE is not set
Fixes: dd13add3ceed ("kernel: i2c-pxa: remove slave")
Signed-off-by: Scott Roberts <[email protected]>