d2: move fstab down from msm8960-common

Change-Id: I51e3ffe464947251c1ae4988b9c49d3d537d7a3c
fstab: mount modem partition with firmware_file context

Change-Id: Ia944e604e43476f3449466c11d63bbc69420329a
Merge changes Ia944e604,I51e3ffe4 into lollipop

* changes:
  fstab: mount modem partition with firmware_file context
  d2: move fstab down from msm8960-common