qpnp: revid: fix the use of TYPE and SUBTYPE

The TYPE for a PMIC chip is always 0x51. There is no need to define it
for each PMIC chip.

Also the SUBTYPE of a PMIC chip doesn't change with versions. Have a
single definition of the SUBTYPE per PMIC chip.

Also, the driver uses integer indexes to get to the pmic name, instead
use the SUBTYPE to index in the pmic names array.

Change-Id: Ie1c43f3db0d4a395307253aad347ad93624a1203
CRs-Fixed: 986619
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>