cxl: remove unnecessary calling of pci_enable_pcie_error_reporting()

With this [1] commit upstream, pci_enable_pci_error_report() is no longer
necessary for the driver to call. Remove call and related cleanups.

[1]: f26e58bf ("PCI/AER: Enable error reporting when AER is native")

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/167632012093.4153151.5360778069735064322.stgit@djiang5-mobl3.local


Signed-off-by: Dan Williams <dan.j.williams@intel.com>