linux-phytec-ti

PCI: endpoint: Protect concurrent access to pci_epf_ops with mutex

Protect concurrent access to pci_epf_ops with mutex. The EPF mutex
added here will also be used to serialize data transfer of a EPF to
the remote RC.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>