geode: fix modular build

-tip testing found this build bug:

 MODPOST 331 modules
 ERROR: "geode_mfgpt_toggle_event" [drivers/watchdog/geodewdt.ko] undefined!
 ERROR: "geode_mfgpt_alloc_timer" [drivers/watchdog/geodewdt.ko] undefined!
 make[1]: *** [__modpost] Error 1
 make: *** [modules] Error 2

with this config:

  http://redhat.com/~mingo/misc/config-Wed_Jun__4_18_01_59_CEST_2008.bad



export those symbols.

Signed-off-by: Ingo Molnar <mingo@elte.hu>