sepolicy: Adress more denials

Tried to fix denials for mounts2sd but
https://github.com/CyanogenMod/android_external_sepolicy/blob/cm-12.0/domain.te#L264
for some reason mounts2sd script tries remount partitions with sysinit
context instead of init.
sepolicy: Override neverallow policy

to permit sysinit remount and execute