board: qualcomm: Add support for dragonboard845c

Add support for 96Boards Dragonboard 845C aka Robotics RB3 development
platform. This board complies with 96Boards Open Platform Specifications.

Features:
- Qualcomm Snapdragon SDA845 SoC
- 4GiB RAM
- 64GiB UFS drive

U-boot is chain loaded by ABL in 64-bit mode as part of boot.img.
For detailed build and boot instructions, refer to
doc/board/qualcomm/sdm845.rst, board: dragonboard845c.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
11 files changed