southbridge/amd/agesa/hudson: Correct incorrect #define

It appears the decimal value was used instead of the hex value.

Change-Id: I04acde9e5b2a9e08ed01b0564c3d561b0385a392
Signed-off-by: Dave Frodin <dave.frodin@se-eng.com>
Reviewed-on: http://review.coreboot.org/7799
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>