PCI: cadence-ep: Remove obsolete path from comment

This comment still refers to the old driver pathname,
when all PCI drivers were located directly under the
drivers/pci directory.

Anyway the function name itself is enough, so we can
remove the overabundant path reference.

Link: https://lore.kernel.org/r/20200623074851.7832-1-f.suligoi@asem.it


Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>