[BSP] Add serial buses PIN mapping and support functions

[elsalahy]

Summary:

Need to add BSP support for the PIN mapping of serial communication pins and their support functions (init() and de-init)

• [x] UART
• [x] I2C1
• [ ] I2C2
• [x] SPI

Why do we need this?

To support com ports initialisation from the BSP lib.

What is already there? What do you see now?

• PIN mapping for GPIO PINS (LEDS, load switches)
• BSP initial structure

What is missing? What do you want to see?

• Serial busses pin mapping.
• Serial busses init and de-init functions

How do you propose to implement this?

See test branches, as everything is implemented, just need to port it to BSP lib and create functions with proper mapping

Environment:

Baremetal

Acceptance Criteria:

• Can compile
• Can communicate over specified buses.

What can you do yourself and what do you need help with?

ALL

[elsalahy]

UART and I2C1 were finished in July milestone, see #32 and #34 Continuing with I2C2 and SPI in August

[elsalahy]

With the end of August, all the referenced above PRs are part of the progress in this issue.

We are missing #55 to close this issue, so it will be moved to September milestone.