ARM: imx: fix name of macros to add imx-i2c devices

This is a follow up to

	c6987159 (ARM: imx: dynamically register imx-i2c devices (imx27))
	2b92084f (ARM: imx: dynamically register imx-i2c devices (imx21))
	6348e6b5 (ARM: imx: dynamically register imx-i2c devices (imx1))

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>