boards: arm: mimxrt1170_evkb: add RT1170 EVKB

Add RT1170 EVKB definition to Zephyr. This board is similar to the
RT1170 EVK, but uses a different quadspi flash chip, and includes
an audio connector as well as an additional display connection.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>