clk: imx: scu: bypass pi_pll enable status restore

PI PLL does not support enable/disable. So bypass it's
enable status restore.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>