soc: imxrt: Fix flexspi xip configuration issue

Fix flexspi xip configuration issue regarding code relocation
due to the order of kconfig defaults being sourced

The flexspi setup was not being relocated to an on chip location

Also remove rt1060 conf file in flash common test which changes the
code relocation location to RAM, just keep as ITCM for all M7 which
as of now all have ITCM from NXP with flexspi.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>