[cosmetic] ara_m: Give a spec reference for the PERM-AR-DO

PERM-AR-DO actually originates in a different spec than all other parts
of the ara_m.py, so let's explicitly mention that.

Change-Id: I6e0014c323f605860d0f70cd0c04d7e461e8a9de
---
M pySim/ara_m.py
1 file changed, 13 insertions(+), 0 deletions(-)

diff --git a/pySim/ara_m.py b/pySim/ara_m.py
index a2eaa33..d137dcf 100644
--- a/pySim/ara_m.py
+++ b/pySim/ara_m.py
@@ -116,6 +116,7 @@
 
 class PermArDO(BER_TLV_IE, tag=0xdb):
     # Android UICC Carrier Privileges specific extension, see https://source.android.com/devices/tech/config/uicc
+    # based on Table 6-8 of GlobalPlatform Device API Access Control v1.0
     _construct = Struct('permissions'/HexAdapter(Bytes(8)))
 
 

