Set AGC mode to fast-attack to align with legacy
DMA changes for T1R1 tests with T2R2 DMA

This keeps the DMA operating in T2R2 mode for consistency with the legacy DMA stack, while
relaxing some restrictions on the userspace tool.  Keeping the DMA in T2R2 mode keeps the
DMA at 64 bits per sample: unused channels are 0-filled on TX and discarded on RX.
Make T2R2 config DTS-only, not allowed at runtime
Cosmetic: reorder comment character priority

Quashes spurious "#: unknown as command or script" message when processing a comment line
containig a URL
Cosmetic: reorder comment character priority

Quashes spurious "#: unknown as command or script" message when processing a comment line
containing a URL
Enable mandatory T2R2 interface timing

Current DMA implementation requires T2R2 regardless of how many channels are active.  This
DTS setting enforces that with a comment regarding the requirement