sepolicy: Allow mediacodec to read sysfs_boot_mode

W omx@1.0-service: type=1400 audit(0.0:3382): avc: denied { read } for name="boot_mode" dev="sysfs" ino=7123 scontext=u:r:mediacodec:s0 tcontext=u:object_r:sysfs_boot_mode:s0 tclass=file permissive=0
E PQ      : [PQ][PQConfig] fail to open: /sys/class/BOOT/BOOT/boot/boot_mode

Change-Id: I1246c6e3290e39968f6fd309c37fcb639178fa14
diff --git a/basic/non_plat/mediacodec.te b/basic/non_plat/mediacodec.te
index c32d8da..f5ade36 100644
--- a/basic/non_plat/mediacodec.te
+++ b/basic/non_plat/mediacodec.te
@@ -151,3 +151,5 @@
 get_prop(mediacodec, vendor_mtk_hdr_video_prop)
 
 hal_client_domain(mediacodec, hal_mtkcodecservice)
+
+allow mediacodec sysfs_boot_mode:file r_file_perms;