imx: imxrt1050-evk: Add support for the NXP i.MXRT1050-EVK

This commit adds board support for i.MXRT1050-EVK from NXP. This board
is an evaluation kit provided by NXP for i.MXRT105x processor family.

More information about this board can be found here:
https://www.nxp.com/design/development-boards/i.mx-evaluation-and-development-boards/i.mx-rt1050-evaluation-kit:MIMXRT1050-EVK



The initial supported/tested devices include:
- Debug serial
- SD

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>