power: Use tmpfs and disable some services

rsyslog, journald, and friends really shouldn't be writing so much to
the emmc or sdcard.

Change-Id: If21f61cfb83a02771568cccb54731da3bae468c2
diff --git a/fstab.emmc b/fstab.emmc
index 3ebf5ef..36592df 100644
--- a/fstab.emmc
+++ b/fstab.emmc
@@ -1,2 +1,3 @@
-/dev/mmcblk0p3 / ext4 defaults 0 1
-/dev/mmcblk0p1 /boot ext2 defaults 0 2
+/dev/mmcblk0p3 / ext4 noatime,defaults 0 1
+/dev/mmcblk0p1 /boot ext2 noatime,defaults 0 2
+tmpfs /var/log tmpfs defaults 0 0
diff --git a/fstab.sdcard b/fstab.sdcard
index 5015290..99b420f 100644
--- a/fstab.sdcard
+++ b/fstab.sdcard
@@ -1,2 +1,3 @@
-/dev/mmcblk1p2 / ext4 defaults 0 1
-/dev/mmcblk1p1 /boot ext2 defaults 0 2
+/dev/mmcblk1p2 / ext4 noatime,defaults 0 1
+/dev/mmcblk1p1 /boot ext2 noatime,defaults 0 2
+tmpfs /var/log tmpfs defaults 0 0