PCI: Don't expose pcie_read_tlp_log() outside PCI subsystem

PCI: Don't expose pcie_read_tlp_log() outside PCI subsystem

pcie_read_tlp_log() was exposed by the commit 0a5a46a6a61b ("PCI/AER:
Generalize TLP Header Log reading") with the intent that drivers could use
it, but the PCI maintainer later decided that drivers should be encouraged
to use PCI core diagnostic logging of generic AER registers rather than
building their own.

Drivers that currently implement their own diagnostic logging include ixgbe
(ixgbe_io_error_detected()) and iwlwifi (iwl_trans_pcie_dump_regs()).

Remove the unwanted EXPORT of pcie_read_tlp_log() and remove it from
include/linux/aer.h.

Link: https://lore.kernel.org/r/20250114170840.1633-2-ilpo.jarvinen@linux.intel.com
Link: https://lore.kernel.org/all/20240322193011.GA701027@bhelgaas/
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>