[lldb][intel-pt] Remove old plugin

[lldb][intel-pt] Remove old plugin

Now that LLDB proper has built-in support for intel-pt traces, we can remove the old plugin written by Intel. It has less features and it's hard to work with.

As a test, I ran "ninja lldbIntelFeatures" and it worked.

Differential Revision: https://reviews.llvm.org/D102866