perf pmu-events: Make pmu-events a library

Make pmu-events into a library so it may be linked against things like
the python module and not built from source.

Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Gary Guo <gary@garyguo.net>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Ze Gao <zegao2021@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andrei Vagin <avagin@google.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: Björn Roy Baron <bjorn3_gh@protonmail.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240625214117.953777-4-irogers@google.com