[coreboot] The default value of TOM (MSRC001_001A) just after Power-On

[Darmawan Salihun]

The default value of MSRC001_001A (Top of Memory below the 4GB limit)
according to BKDG for AMD Fam 10h rev. 3.06 is undefined (after
Reset/power-on).
However, AMD64 Architecture Programmer's Manual Volume 2: System
Programming Rev. 3.14 states that the value of MSRC001_001A
after Reset or power on is: 0000_0000_0400_0000h

Which one of this information is correct?

I need to know it because I want to know what is the default MMIO range
after reset.

Thanks.