[U-Boot] RK3399/RK3288 same-as-spl Option

[Wadim Egorov]

Hi,

I want to know if there is a reason why the same-as-spl boot order
option [1] was not added for the RK3288. Do the chromebooks or other
RK3288 based boards don't want/need this option?

It seems the RK3288 has the same Register that marks the boot source device:
  RK3399_BROM_BOOTSOURCE_ID_ADDR: 0xff8c0010
  For RK3288 it is 0xff700010. I know it is not documented in the TRM.
But it works.

Any opinions in reworking the RK3288 code to use this Register for
"same-as-spl" boot?

[1] https://patchwork.ozlabs.org/cover/812927/

Regards,
Wadim