[SeaBIOS] [PATCH] - Add total usable memory to startup console output

[Damien Zammit]

Hi folks,

I want to put forth this patch for your review.

In my opinion, it is very useful to know just after your machine has
POSTed how much system RAM the machine has access to.

This patch prints out to the screen just under the UUID the following line:
    System RAM: X MB

where X is the number of whole megabytes available to the system.

Since the memory map is already available to SeaBIOS, I think it makes
sense to total up the sizes of regions marked as E820_RAM and print the
grand total.

I have tested this on a coreboot QEMU bios with custom SeaBIOS built:

SeaBIOS (version rel-1.11.0-46-g18e193d)
    System RAM: 1022 MB

When I tried flashing a compatible image to my Lenovo X220 laptop it
bricked it.  I'm not sure why, maybe I compiled it wrong or inserted it
into my image wrongly with cbfstool.

Cheers,
Damien