dumpstate: Collect PCIe link statistics

Collect PCIe link statistics in dump_pcie.sh script.
Move SELinux type declaration 'sysfs_pcie' here.

Test: adb bugreport && unzip bugreport*.zip &&
      grep link_stats dumpstate_board.txt
Bug: 266561593
Change-Id: Iecf3a5a20892efb6d9cc9f4a5c322aafa76f8e7f
Signed-off-by: Doug Zobel <zobel@google.com>

pcie/dump_pcie.sh

@@ -3,3 +3,9 @@ echo "--- pcie0 dump ---"
 cat /dev/logbuffer_pcie0
 echo "--- pcie1 dump ---"
 cat /dev/logbuffer_pcie1
+
+echo "--- pcie link statistics ---"
+for f in /sys/devices/platform/*.pcie/link_stats/*
+do
+  echo "$f: `cat $f`"
+done

pcie/sepolicy/device.te

@@ -1 +1,2 @@
 type pcie_log_device, dev_type;
+type sysfs_pcie, sysfs_type, fs_type;

pcie/sepolicy/dump_pcie.te

@@ -2,3 +2,6 @@ pixel_bugreport(dump_pcie)
 
 allow dump_pcie pcie_log_device:chr_file r_file_perms;
 allow dump_pcie vendor_toolbox_exec:file execute_no_trans;
+
+allow dump_pcie sysfs:dir r_dir_perms;
+allow dump_pcie sysfs_pcie:file r_file_perms;