exynos5420: minor clean-up memory related stuff

This cleans up a few minor things (mostly #defines) of the memory code
for exynos5420, pit, and kirby. Specifically:

- CONCONTROL.empty is read-only, so don't try to set it and also
  get rid of the unneeded DMC_CONCONTROL_EMPTY_ENABLE #define.
- MEMBASECONFIG* overlaps members of the mem_timings struct and
  are mainboard-dependent anyway, so get rid of 'em.
- DMC_MEMCONTROL_TP_DISABLE corresponds to a reserved bit. It may
  have been deprecated.
- Same with TIMING* #defines.
- Clarify DDR_MODE_* usage and use mem->mem_type when appropriate.

Signed-off-by: David Hendricks <dhendrix@chromium.org>
BUG=none
BRANCH=none
TEST=built and booted on pit and kirby

Change-Id: Ideb21efcc97b24f7e115e90051c20daef4480f17
Reviewed-on: https://chromium-review.googlesource.com/167500
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Reviewed-by: ron minnich <rminnich@chromium.org>
5 files changed