[M] Change in coreboot[main]: mb/google/brox: Fix booting to kernel without battery

[Subrata Banik (Code Review)]

Attention is currently required from: Ashish Kumar Mishra, Caveh Jalali, Dinesh Gehlot, Eric Herrmann, Forest Mittelberg, Jayvik Desai, Kapil Porwal, Karthik Ramasubramanian, Keith Short, Krishna P Bhat D, Nick Vaccaro, Paul Menzel, Rishika Raj, Ronak Kanabar, Shelley Chen, Sowmya Aralguppe, Sowmya Aralguppe.

Subrata Banik has posted comments on this change by Sowmya Aralguppe. ( https://review.coreboot.org/c/coreboot/+/83752?usp=email )

Change subject: mb/google/brox: Fix booting to kernel without battery
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Patch Set 19:

(3 comments)

File src/mainboard/google/brox/romstage.c:

https://review.coreboot.org/c/coreboot/+/83752/comment/143c35ab_b854d321?usp... :
PS19, Line 27: MAX_NONTURBO_PERFORMANCE
did you check BootFrequency UPD dump w/o and w/ this CL?

If Cpu Strap already has boot with P1 freq set then I don't follow how this UPD is helpful. Ideally this UPD only comes to the picture if Cpu strap is not set to P1  freq and you wish to override it with P1 freq. Otherwise we always want BIOS to boot with P1 aka HFM and then switch to Turbo after booted to OS.

File src/mainboard/google/brox/variants/baseboard/brox/ramstage.c:

https://review.coreboot.org/c/coreboot/+/83752/comment/6a4abf9b_1b746769?usp... :
PS19, Line 57:  * PL4 calculations - For USB C charger (Max Power):
if we know that OS can override the PL4 table dynamically and we only need to set a lower P4 when battery is not present. Then, it would be good to boot with a static configuration which is safest and generically applicable.

Adding logic to configure PL4 based on USB-PD capacity seems overdoing for BIOS.

File src/mainboard/google/brox/variants/brox/ramstage.c:

https://review.coreboot.org/c/coreboot/+/83752/comment/c6fc25bd_dbb7d884?usp... :
PS19, Line 19: 		.pl1_min_power = 15000,
this change should  be part of separate CL