Broadwell/Sata: Add support for setting IOBP registers for Ports 2 and 3.

The Broadwell SATA controller supports IOBP registers on ports 0 and 1 but
Browell supports up to 4 ports, so we need to support setting IOBP for
ports 2 and 3 as well.
The magic numbers (IOBP SECRT88 and DTLE) for ports 2 and 3 were only
guessed by looking at ports 0 and 1 and extrapolating from there.
Port 3 has been tested (DTLE setting on Librem 13) and confirmed to work
so we can assume that port 2 and 3 magic numbers are valid, but having
someone confirm them (through non-public documents?) would be great.

Change-Id: I59911cfa677749ceea9a544a99b444722392e72d
Signed-off-by: Youness Alaoui <youness.alaoui@puri.sm>
Reviewed-on: https://review.coreboot.org/18408
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
3 files changed