bhnd(4): Implement missing support for specifying I/O control flags during core reset.

[landonf]

Summary

These changes are required to support attaching bwn(4) via bhnd(4).

Depends on D13021

Test Plan

Tested against bcma(4) and siba(4) MIPS and PCI(e) targets.

[landonf]

Fix bhnd_usb(4) build.

[landonf]

• Implement missing support for specifying I/O control flags during core reset.
• Add missing check for siba(4) target reject flags in bhnd_is_hw_suspended()
• Fix siba(4) core suspend/reset behavior:
  • We don't need to wait on SIBA_TMH_BUSY when modifying any target state register; only when waiting for initiated transactions to clear.
  • We do need to wait on SIBA_IM_BY when asserting SIBA_IM_RJ.
  • We need to overwrite any previously set SIBA_TML_REJ flag when bringing the core out of reset. This fixes a lockup that occured when we brought up a core (after reboot) that had previously been placed into RESET by siba_bwn(4).