Remove the common 'platform' registration module, and move the crypto
compression driver registration into each of the pSeries and PowerNV
platform NX 842 drivers.  Change the nx-842.c code into simple common
functions that each platform driver uses to perform constraints-based
buffer changes, i.e. realigning and/or resizing buffers to match the
driver's hardware requirements.

The common 'platform' module was my mistake to create - since each
platform driver will only load/operate when running on its own
platform (i.e. a pSeries platform or a PowerNV platform), they can
directly register with the crypto subsystem, using the same alg and
driver name.  This removes unneeded complexity.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>