can: mcp25xxfd: Add Microchip mcp25xxfd CAN FD driver basics

This patch adds basic driver support for the Microchip mcp2517fd
CAN-FD controller.

The mcp2517fd is capable of transmitting and receiving standard data
frames, extended data frames, remote frames and Can-FD frames.
The mcp2517fd interfaces with the host over SPI.

This patch iprovides basic driver functionality:
setting up clocks and the infrastructure for the can and gpio portions
of the driver.

Change-Id: I440ea49d7b88ca7c6d2b7626a08f2a7685fe65f5
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Git-commit: 77038ce6
Git-repo: https://github.com/msperl/linux-rpi/releases/tag/mcp25xxfd-V8.2


Signed-off-by: Ke Du <quic_kedu@quicinc.com>