[PATCH] Add imx93-var-som support

[Mathieu Othacehe]

Hello Fabio,

Thanks for the review!

> It would also be helpful to add doc/board/variscite/imx93_var_som.rst
> that explains
> how to build U-Boot for this board, how to get the firmware, ATF,
> binaries, etc, and how to flash it to the boot medium.

For now, I am testing the bootloaders I produce using those
instructions:
https://variwiki.com/index.php?title=Yocto_Build_U-Boot&release=mx93-yocto-mickledore-6.1.36_2.1.0-v1.1

I understand that it would be nice to have u-boot do the image
construction with the firmware, ATF and so on, like implemented on
imx8.

Do you think that it could be done in a follow-up patch, once
imx93-var-som support is merged?

> Please also submit the imx93-var-som-symphony.dts support to Linux so that
> it can get reviewed by the DT folks.

Done here:
https://lore.kernel.org/linux-devicetree/20231227170919.8771-1-othacehe@gnu.org/T/#t

> To not block the board support, I suggest sending a v2 without PTN5150
> support for now.

OK.

>> +/* Using ULP WDOG for reset */
>> +#define WDOG_BASE_ADDR          WDG3_BASE_ADDR
>
> Is this needed now that we use DM?

That specific define is needed as the ulp_wdog driver seems to require
it. I removed all the other unneeded defines in v2.

Thanks,

Mathieu