clk: imx: clk-pll14xx: Make two variables static

Fix sparse warnings:

drivers/clk/imx/clk-pll14xx.c:44:37:
 warning: symbol 'imx_pll1416x_tbl' was not declared. Should it be static?
drivers/clk/imx/clk-pll14xx.c:57:37:
 warning: symbol 'imx_pll1443x_tbl' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>