drivers: flash/memc: Source logging kconfig last

Some flash/memc drivers like flexspi will want to default the
value of the log level to off to avoid RWW hazard while XIP,
to do this, the logging template must be sourced after the driver
kconfig files so that the default value from the driver is able
to be checked, since logging template introduces an unconditional
default otherwise.

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