Add ppc64le support

[drchristensen]

Unable to use GitVersion application on Linux systems with ppc64le architecture. For example:

$ dotnet-gitversion /home/user/src/GitVersion
The type initializer for 'LibGit2Sharp.Core.NativeMethods' threw an exception.

Add support to build native ppc64le binaries along with other supported CPU architectures.

[bording]

I have questions about this change.

First, what sort of machine are you using that even has this sort of processor in it?

Second, where did you get a .NET distribution that works on it? Microsoft doesn't support or ship .NET for anything other than x64, arm32, and arm64.

[drchristensen]

IBM, Microsoft and RedHat have announced support for .NET 7/8 on POWER, you can find out more about it on the IBM .NET blog. Microsoft supports installing .NET on Linux as described here. In my use case, I'm building a project on Fedora 40 in a VM hosted on a P9 PowerNV system. Installing the GitVersion tool is as simple as running dotnet tool install --global GitVersion.Tool.

[drchristensen]

The blog post also mentions support for IBM s390x mainframes, though I don't think the build containers used actually had the appropriate s390 cross compilers.

[bording]

Ok, so it's specifically Red Hat that is building a shipping .NET for that architecture.

Can you run dotnet --info and provide the output here? I want to confirm a few things (like what the RID actually shows up as) before merging this.

[bording]

Also, it doesn't seem like we'd need the musl variation since RHEL uses glibc and not musl.

[bording]

@drchristensen I went ahead and pulled your changes into another branch and made some tweaks (and I needed to rebase anyway to react to changes from #160) : #161