- Call the RiscPC mouse "CONFIG_MOUSE_RISCPC" not "CONFIG_MOUSE_ACORN"
- Remember the last state of the buttons so we're not continuously
  reporting this to the core input subsystem.
- Correct mapping of bits to buttons
- Correct button sense (1 = released)
- Always pass a dev_id when requesting an IRQ.  Required for SA_SHIRQ
  shared interrupts.
- Merge ARM keyboard controller config options
- General update for rpckbd.c