mb/dell: Add OptiPlex 7020/9020 port

The OptiPlex 7020 and 9020 use physically identical motherboards.

WARNING: PWM fan control doesn't work via the EC and the fan runs at a
fixed speed. There is likely more EC init to reverse engineer.

Each model comes in the following form factors:
- 7020: SFF, MT
- 9020: USFF (not currently supported), SFF, MT

(7020 SFF) Boots Linux and Windows 10:
- Tested with an i3-4160 and i5-4460
- DRAM init works using the MRC (4G, 4G+4G)
- iGPU init works using libgfxinit (VGA, 2x DP)
- PCIe 16x: tested, ok
- PCIe 4x: tested, ok
- All USB2 and USB3 ports work
- SMSC SCH5555 Super I/O: serial works, PS/2 untested
- Audio: back and front output works, internal speaker works,
         mic inputs untested
- Ethernet: tested, works

(9020 MT)
- Tested by Michael Büchler (thanks for the overridetree)

Change-Id: Ie7c7089f443aef9890711c4412209bceb1f1e96a
Signed-off-by: Mate Kukri <kukri.mate@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55232
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nicholas Chin <nic.c3.14@gmail.com>

0 files changed, 0 insertions, 0 deletions