geode-mfgpt: restore previous behavior for selecting IRQ

geode-mfgpt: restore previous behavior for selecting IRQ

geode-mfgpt: restore previous behavior for selecting IRQ

The MFGPT IRQ used to be, in order of decreasing priority,
 * IRQ supplied by the user as a boot-time parameter,
 * IRQ previously set by the BIOS or another driver,
 * default IRQ given at compile time.

Return to this behavior, which got broken when splitting the
MFGPT/clocksource driver for 2.6.33-rc1.

Signed-off-by: Jens Rottmann <[email protected]>
Acked-by: Andres Salomon <[email protected]>
Cc: Jordan Crouse <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: john stultz <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>