spmi: Rename qpnp library to be part of the spmi framework

It turns out that the only use cases for the qpnp library use
the existing spmi data structures. As such, there's really
no justification for having the library not be called 'spmi'.
There is nothing Qualcomm specific about this code.

Also cleanup some inconsistencies in the Kernel Doc comments
while we're here.

Change-Id: I1c73c88be740b6f5d38ba2de62de1737981b30fa
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>