[coreboot] [PATCH] Multiboot bugfix (coreboot-v3)

[Robert Millan]

Hi,

I noticed a problem in the multiboot memory map in v3.  Instead of the
reserved region:

addr=0x0, len=0x500

we get:

addr=0x0, len=0x10

the reason being that the multiboot map is generated too early in
arch_write_tables(), before a number of routines that write/reserve
stuff are executed (in my test this only affects the 0x0-0x500 region
but I notice there's other stuff too).

Attached patch moves it down, solving the problem.  Because stage1 can no
longer assume the MBI is at 0xf0000, I had to add a return path for stage2
to give it a pointer, using its exit status value.

As collateral benefit, my patch removes the FIXME about PIRQ alignment.