The AMD dbm690t mainboard uses the it8712f SIO with the

The AMD dbm690t mainboard uses the it8712f SIO with the
default 48MHz clock input. The Asus a8n_e uses the it8712f
with a 24MHz clock input. The it8712f early init code was
setting a 24MHz input clock(to support the a8n_e).
Since 48Mhz is the default I added a function to set 24MHz
input clock to the a8n_e.

Signed-off-by: Marc Jones <marc.jones@amd.com>
Acked-by: Rudolf Marek <r.marek@assembler.cz>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3594 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1