Drop useless mainboard-romstage defines

Some src/mainboard/*/*/romstage.c files use defines which later
modify the behaviour of included .c files.
Since it's a pain to work out what is affected by these, drop
values that are only defined in the board but never used, or
defined to identical values as in spd.h (and use that one instead).

Change-Id: I8143b26fddc32a40ac4e611a6287bf7f144267dc
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/5639
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
AMD: Drop redundant test for CONFIG_RAMTOP

Same test is already done in x86/mtrr.h.

Change-Id: Ib0785d047567374294b9ee7afc4f4244f9ced926
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5620
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>