i2c: imx-lpi2c: return -EINVAL when i2c peripheral clk doesn't work

On MX8X platforms, the default clock rate is 0 if without explicit
clock setting in dts nodes. I2c can't work when i2c peripheral clk
rate is 0.

Add a i2c peripheral clk rate check before configuring the clock
register. When i2c peripheral clk rate is 0 and directly return
-EINVAL.

Signed-off-by: Carlos Song <carlos.song@nxp.com>
Acked-by: Dong Aisheng <Aisheng.dong@nxp.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>