0/2 Add support for maple "Visual Memory Unit" on SEGA Dreamcast]

Apologies: sent it to the wrong address for this list before

The VMU is a small (approx 128K) hotpluggable flash device on the SEGA Dreamcast.

To get this to work I have had to rewrite parts of the maple bus driver - some of that is bug fixing (in the sense that the bus driver was not allowing proper probing, just forcing the load of the appropriate driver) - the main functional change is to add a semaphore to the maple device (to ensure that devices can properly inject maple packets into the queue of packets waiting to be dispatched via DMA to the devices themselves).

 drivers/mtd/maps/Kconfig     |   14 +
 drivers/mtd/maps/Makefile    |    1 +
 drivers/mtd/maps/vmu_flash.c |  746 ++++++++++++++++++++++++++++++++++++++++++
 drivers/sh/maple/maple.c     |  113 ++++---
 include/linux/maple.h        |    2 +