dumpstate: dump dock status

Dump /sys/class/switch/dock/dock_status
No such device = no dock detected
0x00 = none
0x04 = 500mA
0x08 = 2A
0x0c = 1A

Bug: 7245314

Change-Id: Idbbf007c4394ece6615aa89454e4ef64347b122a
diff --git a/dumpstate/dumpstate.c b/dumpstate/dumpstate.c
index a922981..07149b2 100644
--- a/dumpstate/dumpstate.c
+++ b/dumpstate/dumpstate.c
@@ -31,6 +31,7 @@
     dump_file("touchscreen name", "/sys/class/input/input0/name");
     dump_file("android power", "/d/android-power");
     dump_file("manta power", "/d/manta-power");
+    dump_file("dock status", "/sys/class/switch/dock/dock_status");
     dump_file("smb347 charger regs", "/d/smb347-regs");
     dump_file("ds2784 fuel gauge regs", "/d/ds2784");
     dump_file("bus traffic shaper", "/d/bts_dev_status");