tee: allow access to DRM files.

Fixes the following denials:

<5>[   30.703885] type=1400 audit(1386698221.792:59): avc:  denied  { getattr } for  pid=271 comm="qseecomd" path="/persist/widevine/5dsokxEEDXgQhkN50bp-Z2K5InM_/RXFABDUxyT6Q+Zwx9ZhPGOq2Bq8_" dev="mmcblk0p16" ino=22 scontext=u:r:tee:s0 tcontext=u:object_r:persist_drm_file:s0 tclass=file
<5>[   30.704413] type=1400 audit(1386698221.792:60): avc:  denied  { read } for  pid=271 comm="qseecomd" name="RXFABDUxyT6Q+Zwx9ZhPGOq2Bq8_" dev="mmcblk0p16" ino=22 scontext=u:r:tee:s0 tcontext=u:object_r:persist_drm_file:s0 tclass=file
<5>[   30.704539] type=1400 audit(1386698221.792:61): avc:  denied  { open } for  pid=271 comm="qseecomd" name="RXFABDUxyT6Q+Zwx9ZhPGOq2Bq8_" dev="mmcblk0p16" ino=22 scontext=u:r:tee:s0 tcontext=u:object_r:persist_drm_file:s0 tclass=file

Change-Id: Ic4d471672e1cb334695e5b3f199ac5225f1d758b
diff --git a/sepolicy/tee.te b/sepolicy/tee.te
index 4535f6d..2e0670a 100644
--- a/sepolicy/tee.te
+++ b/sepolicy/tee.te
@@ -9,3 +9,4 @@
 # Read from persist partition
 allow tee persist_file:dir search;
 r_dir_file(tee, persist_data_file)
+r_dir_file(tee, persist_drm_file)