Hi,

after moving crt0s and lscripts away from the mainboards' Makefiles,
those Makefiles are rather simple now, with more opportunities to move
out things.

Attached patch does:
- make HAVE_HARD_RESET match what newconfig did
- introduce BOARD_HAS_HARD_RESET and use it if a board provides
hard_reset in $(MAINBOARDDIR)/reset.c, instead of some chipset component
- move a couple of rules out of the mainboards' Makefiles into
src/arch/i386/Makefile.inc:
       initobj-y += crt0.o
       obj-y += mainboard.o
       obj-$(CONFIG_GENERATE_MP_TABLE) += mptable.o
       obj-$(CONFIG_GENERATE_PIRQ_TABLE) += irq_tables.o
       obj-$(CONFIG_BOARD_HAS_HARD_RESET) += reset.o
- remove Makefile.incs that are empty (or comment-only) after these
changes, incl. Makefile.romccboard.inc (and references to it)
- Make include not fail if file doesn't exist.

reset.o used to be HAVE_HARD_RESET, but to make this rule more
universal, that new variable had to be introduced.

It's build tested and has no regression vs. current HEAD (ie. the same
two boards fail for the same reason) and is boot tested on kontron/986lcd-m.

Signed-off-by: Patrick Georgi <patrick.georgi@coresystems.de>