pci: build on Windows

pci: build on Windows

Added <sys/types.h> in rte_pci header file
to include off_t type since it is missing for Windows.

Define the implementation of the Linux function rte_pci_get_sysfs_path
in pci_common.c for Linux OS only as it is unneeded for other OSs
and to avoid the warning on deprecated call to getenv() on Windows:

"warning: 'getenv' is deprecated: This function or variable may be unsafe.
Consider using _dupenv_s instead."

Signed-off-by: Tal Shnaiderman <talshn@mellanox.com>