[coreboot] [MSRTOOL][PATCH] Add Geode GX2 processor support.

[Nils]

Hello all,
The attached patch (for review) brings support for the AMD Geode GX2 
processors to Msrtool.
It seems to work as i tested it on my Wyse Winterm S50.

Signed-off-by: Nils Jacobs

Msrtool -l -s output(+ File attached):

msrtool 4966M
Detected system linux: Linux with /dev/cpu/*/msr
Detected target geodegx2: AMD Geode(tm) GX2
Detected target cs5536: AMD Geode(tm) CS5536

Thanks,Nils