The attached patch puts support for Sandpoint X2 back into Linux 2.6.
Unlike my previous attempts, this patch detects the Sandpoint model at
runtime. I only have an X2 here, so I would appreciate reports of the
code being unbroken on the X3.

The patch causes EPIC_SERIAL_MODE to be a runtime rather than compile
time decision. It also changes the UART interrupts from level to edge,
which on my X2 is required in order to work with the serial driver in
2.6. I'd also like to know if this breaks the X3.

Any comments?

- Adrian Cox
Humboldt Solutions Ltd.