i.MX8 LPI2C requires both PER and IPG clock, so add the missed IPG clk.
Reviewed-by: NDong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: NPeng Fan <peng.fan@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>