time: Add T_First constant

The constant can be used to initialize variables of type HW.Time.T.

Change-Id: I65246d6776d464bfa8648075b48e7de61cd82902
Signed-off-by: Adrian-Ken Rueegsegger <ken@codelabs.ch>
Reviewed-on: https://review.coreboot.org/c/libhwbase/+/38983
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Nico Huber <nico.h@gmx.de>
1 file changed