i2c: imx: add INT flag and IEN bit operatation codes

This add bits operation macro that differ between SoCs.
Interrupt flags clear operation in I2SR differ between SoCs:
write zero to clear(w0c) INT flag on i.MX,
but write one to clear(w1c) INT flag on Vybrid.
I2C module enable operation in I2CR also differ between SoCs:
set I2CR_IEN bit enable the module on i.MX,
but clear I2CR_IEN bit enable the module on Vybrid.

Signed-off-by: Jingchang Lu <b35083@freescale.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>