[PATCH] ram: k3-ddrss: Handle error properly in lpddr4_start

[Bryan Brattlof]

On August 29, 2024 thus sayeth Udit Kumar:
> In lpddr4_start function error returned by lpddr4_enablepiinitiator
> may go undetected due to overwrite of return code.
> Add support to handle error in above case.
> 
> Reported-by: Andreas Dannenberg <dannenberg at ti.com>
> Signed-off-by: Udit Kumar <u-kumar1 at ti.com>

Reviewed-by: Bryan Brattlof <bb at ti.com>

One day I'll get around to cleaning this up. starting the controllers 
isn't all this complicated.  

~Bryan