docs: Fix dts & no-os links in obsolete docs

[StancaPop]

PR Description

Fix the links for dts & no-os sources in the obsolete projects' documentation.

PR Type

• Bug fix (change that fixes an issue)
• New feature (change that adds new functionality)
• Breaking change (has dependencies in other repos or will cause CI to fail)
• Documentation

PR Checklist

• I have followed the code style guidelines
• I have performed a self-review of changes
• I have compiled all hdl projects and libraries affected by this PR
• I have tested in hardware affected projects, at least on relevant boards
• I have commented my code, at least hard-to-understand parts
• I have signed off all commits from this PR
• I have updated the documentation (wiki pages, ReadMe files, Copyright etc)
• I have not introduced new Warnings/Critical Warnings on compilation
• I have added new hdl testbenches or updated existing ones

[StancaPop]

Note: For the ad_fmclidar1_ebz, the last HDL release is set to hdl_2021_r1, but on the Linux side, in the 2019_R1 release, the a10soc link wasn't working. I switched all the links to 2019_R2, since they are still supported there. Any comments on this? Should I keep the links to 2019_R1 for the other devicetrees?