modemmanager: fix physdev sysfs path detection in PCIe modems

The PCIe physdev path lookup relies on the 'vendor' and 'device'
attribute files, instead of the 'idVendor' and 'idProduct' ones, which
are USB specific.

Signed-off-by: Aleksander Morgado <aleksander@aleksander.es>

net/modemmanager/files/modemmanager.common

@@ -39,12 +39,21 @@ mm_find_physdev_sysfs_path() {
 		# avoid infinite loops iterating
 		[ -z "${tmp_path}" ] || [ "${tmp_path}" = "/" ] && return
 
-		# the physical device will be that with a idVendor and idProduct pair of files
+		# For USB devices, the physical device will be that with a idVendor
+		# and idProduct pair of files
 		[ -f "${tmp_path}"/idVendor ] && [ -f "${tmp_path}"/idProduct ] && {
 			tmp_path=$(readlink -f "$tmp_path")
 			echo "${tmp_path}"
 			return
 		}
+
+		# For PCI devices, the physical device will be that with a vendor
+		# and device pair of files
+		[ -f "${tmp_path}"/vendor ] && [ -f "${tmp_path}"/device ] && {
+			tmp_path=$(readlink -f "$tmp_path")
+			echo "${tmp_path}"
+			return
+		}
 	done
 }