perf/x86/intel/uncore: Factor out uncore_pci_pmu_unregister()

The PMU unregistration in the uncore PCI sub driver is similar as the
normal PMU unregistration for a PCI device. The codes to unregister a
PCI PMU can be shared.

Factor out uncore_pci_pmu_unregister(), which will be used later.

Use uncore_pci_get_dev_die_info() to replace the codes which retrieve
the socket and die informaion.

The pci_set_drvdata() is not included in uncore_pci_pmu_unregister() as
well, because the uncore PCI sub driver will not touch the private
driver data pointer of the device.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1600094060-82746-5-git-send-email-kan.liang@linux.intel.com