block: support volname for HTC devices with proc/emmc support

gets data from emmc_partitions and write it down on mmcblk0pX partitions
this enables vold by-name mappings

Change-Id: I4af7f34919ae1e94b960fcabfcfb70fe50825cf7
Merge remote-tracking branch 'cm/cm-11.0' into cm-11.0
Merge branch 'cm-11.0' into 8660-tp-merge