x86, gart: Convert spaces to tabs in enable_gart_translation

Probably by copy&paste this function was indented by spaces.
Convert this to tabs.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Link: http://lkml.kernel.org/r/1303134346-5805-3-git-send-email-joerg.roedel@amd.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>