[SeaBIOS] ram_probe() displays wrong size for RamSizeOver4G

[Sebastian Herbszt]

I have modified Bochs to support the needed cmos bytes for specifying
memory above pci hole. If i set it up to 5120 MB i get the following:
00000271154i[BIOS ] Ram Size=0xc0000000 (0xffffffff80000000 high)
The "high" value looks odd (upper 32 bit should be 0).

- Sebastian