Standardise header guards across codebase ...

All identifiers, regardless of use, that start with two underscores are
reserved. This means they can't be used in header guards.

The style that this project is now to use the full name of the file in
capital letters followed by 'H'. For example, for a file called
"uart_example.h", the header guard is UART_EXAMPLE_H.

The exceptions are files that are imported from other projects:

- CryptoCell driver
- dt-bindings folders
- zlib headers

Change-Id: I50561bf6c88b491ec440d0c8385c74650f3c106e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

drivers: mentor: extract MI2CV driver from Marvell driver ...

The Marvell A8K SoCs use the MI2CV IP core from Mentor Graphics, which
is also used by Allwinner.

As Mentor Graphics allows a lot of customization, the MI2CV in the two
SoC families are not compatible, and driver modifications are needed.

Extract the common code to a MI2CV driver.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>