rusb2: fix SQCLR/ACLRM preconditions and RA6M5 USBHS pipe handling (#4146)

- pipe_reset(): reach PID=NAK and PBUSY=0 out of CURPIPE before SQCLR/ACLRM, hold ACLRM >=100 ns
- RA6M5 USBHS: per-pipe PIPEBUF; park OUT packets that arrive unarmed instead of dropping them
- keep a halt when a transfer is submitted on a halted pipe; quiesce pipes on close; EP0 drain completes in the caller's context
- RA: no .bin except dfu-util boards; HIL: ra6m5_ek with openocd reset recovery

Fixes #4038, closes #4150