drivers: flash: flexspi: Fix XIP during flash write

Commit 857e5793 fix
the flash_mcux_flexspi_nor.c driver to wait for the
FlexSPI to be idle before performing write/erase
operations. Add a similar check to these drivers that
also use the FlexSPI NOR block.

Signed-off-by: Mahesh Mahadevan <mahesh.mahadevan@nxp.com>