northbridge/amd/{lx,gx2}: remove immediate accesses of 0

gcc doesn't like these because they're undefined behavior, so use
zeroptr instead. For the loop that just does a number of writes (0..4),
use zeroptr + i.

Checked the disassembly (AMD_RUMBA and PCENGINES_ALIX2D) to not contain
ud2 anymore and to look reasonable where zeroptr was used.

Change-Id: I4a58220ec9a10c465909ca4ecbe5366d0a8cc0df
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/14345
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)

0 files changed, 0 insertions, 0 deletions