[PATCH 5/9] ram: k3-ddrss: Add exit retention support

[Bryan Brattlof]

Hi Thomas!

On October 16, 2023 thus sayeth Thomas Richard:
> Add the exit retention support.
> The enter retention is done by DM-Firmware.
> A part of the exit retention sequence is specific to the board.
> It is done in board_k3_ddrss_lpddr4_release_retention.
> 
> Based on the work of Gregory CLEMENT <gregory.clement at bootlin.com>
> 
> Signed-off-by: Thomas Richard <thomas.richard at bootlin.com>
> Signed-off-by: Gregory CLEMENT <gregory.clement at bootlin.com>
> ---
> 
>  drivers/ram/k3-ddrss/k3-ddrss.c | 302 ++++++++++++++++++++++++++++++++
>  1 file changed, 302 insertions(+)
>

Do you mind putting this behind some type of Kconfig option? For the 
am62* class of devices the amount of SRAM we have is really stretched 
thin. I'm worried this may put us over the top. 

~Bryan