clk: imx7ulp: Include clk-provider.h instead of clk.h

The i.MX7ULP clock driver is provider, NOT consumer, so clk-provider.h
should be used instead of clk.h.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>