vendorcode/amd/agesa/f15tn: Fix assembly bugs

Found missing '$' symbol on variable.

Change-Id: I748c315adc44598e16283f8e629be0ecfe9cb6a9
Signed-off-by: Damien Zammit <damien@zamaudio.com>
Reviewed-on: http://review.coreboot.org/7514
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
3 files changed