tegra3-common: Fix some permissions

Fixes the following errors on boot.

E/HtcCameraHal(  151): [CAM] [Calibration] open file ["/data/factory_main.bin"] failed, errno = 13 (Permission denied)

E/hwcomposer(  148): /sys/class/graphics/fb0/device/smartdimmer/enable: open failed: Permission denied
E/hwcomposer(  148): Failed to set initial DIDIM status to disable

E/nvaudio_hw(21838): open failed of sysfs entry /sys/power/suspend/mode
E/nvaudio_hw(21838): Error in save_lp_mode

Change-Id: I98a32a39a66f88f7dff3a4ab1ada867aaabff568