Fix: adiv5/6 JTAG version handling

[dragonmux]

Detailed description

This PR addresses a mistake made in the way that we handle DP versioning for JTAG-DPs in ADIv5 and v6.

ADIv5 implements protocol version 0, while ADIv6 implements version 1. This is a totaly different thing to the detectable version from the JTAG IDCODE PARTNO field which is related to the DP version instead.

We correct the low-level handling in adiv5_jtag.c with this, so that DPv0-2 work properly as protocol v0, while DPv3+ are protocol v1. This allows the PARTNO -> version translation to then be corrected and handled more appropriately.

Tested on a LPC4370.

Your checklist for this pull request

• I've read the Code of Conduct
• I've read the guidelines for contributing to this repository
• It builds for hardware native (see Building the firmware)
• It builds as BMDA (see Building the BMDA)
• I've tested it to the best of my ability
• My commit messages provide a useful short description of what the commits do

Closing issues

[ALTracer]

Tested on GD32E508.

Can confirm, this is as good or better than before, on this chip.
Before PR2053 (fails):

Black Magic Debug App v2.0.0-rc1-17-g6585197c
...
ID code 0x0ba04477: ADIv5 JTAG-DP port.
ID code 0x790007a3: Gigadevice BSD.
Unknown JTAG-DP found, please report partno code ba04
Not using ADIv5 acceleration commands
DP DPIDR 0x0be11477 (v1 MINDP rev0) designer 0x43b partno 0xbe
> JTAG access resulted in fault
...
> JTAG access resulted in fault
adiv5: power-up failed
Given target number 1 not available max 0

With PR2053: (DPv0)

Black Magic Debug App v2.0.0-rc1-18-gcff3b4e6
...
ID code 0x0ba04477: ADIv5 JTAG-DP port.
ID code 0x790007a3: Gigadevice BSD.
DPv0 detected based on JTAG IDCode
AP   0: IDR=14770015 CFG=00000000 BASE=e00fe000 CSW=a3800040 (AHB5-AP var1 rev1)

With this PR2054: (DPv1, MINDP, has DPIDR, uses ABORT not CTRL/STAT)

Black Magic Debug App v2.0.0-rc1-21-g868b41d8
ID code 0x0ba04477: ADIv5 JTAG-DP port.
ID code 0x790007a3: Gigadevice BSD.
DP DPIDR 0x0be11477 (v1 MINDP rev0) designer 0x43b partno 0xbe
AP   0: IDR=14770015 CFG=00000000 BASE=e00fe000 CSW=a3800040 (AHB5-AP var1 rev1)

Firmware produces identical logging on blackpill-f4.

Thanks for restoring operation.

[esden]

LGTM