vboot2: Fix compiler flags dropped during verstage/libverstage split

verstage still needs to be built with its flags.

Change-Id: I125e4be283d3838fc7ce6587bf9996731540d517
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10098
Tested-by: build bot (Jenkins)
1 file changed