Add AXI-AD3552R

[machschmitt]

Add the AXI-AD3585R DAC driver which adapts AD3585R for use with ad3552r_evb HDL project.

Comments:

• Add AXI-AD3585R platform driver.
• dt-binding documentation leveraged by upstream version.
• There is a second HDL project which uses the AXI-AD3585R driver and that one also depends on updated versions of MathWorks drivers from PR #2193. I left the changes related to that project to a follow-up PR.