MLK-17317 arm: imx: add no_console_suspend support for i.mx7ulp vlls mode

MLK-17317 arm: imx: add no_console_suspend support for i.mx7ulp vlls mode

LPUART driver currently turns off clocks during device
suspend phase, but in i.MX7ULP platform low level suspend
routine, lpuart will be saved/restored during suspend/resume,
to avoid system hang caused by accessing lpuart registers
without clocks enable, add console_suspend_enabled check for
lpuart register save/restore.

SCG1 SOSCDIV register needs to be saved/restored anyway,
move it to asm code, all SCG1 registers will be restored
there.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Rviewed-by: Bai Ping <ping.bai@nxp.com>