drivers: clock_control: smartbond: Add support for the memc driver.

1. Update the clock control driver so it can update timing settings for
   QSPIC2 following system clock transitions (translated based on
   AHB AMBA bus clock).
2. Remove the QSPIC related subroutines and use the respective HAL API
   which is now available.
3. Add support for PM (CONFIG_PM_DEVICE). This is required as QSPIC2
   register file is powered by PD_SYS which is turned off during device
   sleep and so registers contents are lost (in contrast to QSPIC which
   is used to drive the flash memory).

Signed-off-by: Ioannis Karachalios <ioannis.karachalios.px@renesas.com>