dt-bindings: i2c: imx: add SoC specific compatible strings for S32G

S32G2 and S32G3 SoCs use the same I2C controller as i.MX.
But there are small differences such as specific
<clock divider, register value> pairs.
So add new compatible strings 'nxp,s32g2-i2c'and 'nxp,s32g3-i2c'
for S32G2/S32G3 Socs.

Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>