x86/PCI: Drop 'pci' suffix from intel_mid_pci.c

CE4100 PCI specific code has no 'pci' suffix in the filename,
intel_mid_pci.c is the only one that duplicates the folder name in its
filename, drop that redundancy.

While at it, group the respective modules in the Makefile.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Link: https://patch.msgid.link/20250407070321.3761063-1-andriy.shevchenko@linux.intel.com