PCI/AER: Export pci_aer_unmask_internal_errors()

PCI/AER: Export pci_aer_unmask_internal_errors()

Internal PCIe errors are not enabled by default during initialization
because their behavior is too device-specific and there is no standard way
to reason about them. However, for CXL an internal error is the standard
mechanism for conveying CXL protocol errors.

Export pci_aer_unmask_internal_errors() for CXL, but make it clear that
they are only meant for CXL and the status quo for leaving them masked for
PCIe in general remains.

Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260114182055.46029-10-terry.bowman@amd.com
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>