[coreboot] UNTIN casting errors

[Anthony Ross]

Hello all
Well the corebootPkg has been one of the best to be incorporated in the
edk2 source code. For those who contain large EEPROMs would actually be
lucky to try it out on real hardware. Well coming to the point the
corebootpkg had some fixes done last time like the toolchain errors on X64
architectures. But some like the casting errors contained in the
PlatformPie/Memdect.c have not been fixed yet. Suggestions were last time
given of UNTIN cast prior to casting to a pointer but the edk2 corebootpkg
gitrepo contains no changes pushed.

I hope so someone on this mailing list would pay heed and do the needful. I
had mailed the author directly concerning the changes but nothing has been
reflected.

Neo