imx_lpi2c: Update lpi2c driver to support imx8

Add compatible string for i.MX8 and move imx_lpi2c.h from mx7ulp directory
to u-boot include directory as a common header file.

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
2 files changed