dumpstate: Dump eMMC 5.0 stats

Extended csd EXT_CSD_REV, PRE_EOL_INFO, DEVICE_LIFE_TIME_EST_TYP_A,
and DEVICE_LIFE_TIME_EST_TYP_B fields printed if available. Allow
dumpstate access to /sys/kernel/debug/mmc0/mmc0:0001/ext_csd.

Bug: 24200279
Change-Id: I310bdcf546a9307cf927f109359ad5a6d24b70f8