dts: move frdm_k64f flash partitions from SoC dtsi

Currently, flash partitions used by mcuboot are defined in the
SoC-level dtsi file for NXP K6X. This should be made more granular so
that product owners can choose partition layouts to suit their
needs. To that end, move the partitions into frdm_k64f.dts.

Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>
2 files changed