ARM: dts: msm: fix qfprom register bits field for sdm670

Qfprom bit offset field expects value bitween 0-7
(Documentation/devicetree/bindings/nvmem/nvmem.txt).  This change fixes
commit 614664b8a1e2 ("ARM: dts: msm: Add qfprom node for sdm670").

Set bits offset to 0 and read number bits to desired offset. Client would
need to extract desired bits from the read value.

Use QFPROM RO register instead of RW.

Change-Id: If8ab33a4f019309b3d99dfdb2849e361206aa0f6
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>