- Detect dropped words at the dispatch level. This prevents
an overflow on CHDR from block CPU.
- Dropped packets are recorded as CPU or CHDR drop count
- Refactor to put chdr_xport_adapter.sv in different clock
domain to improve timing
- Unwrinkle tkeep/trailing transitions
Original-commit: 7f86724ec3387f75d39d683b2ac5f5152e714c74