crypto: omap-des - Add omap-des driver for OMAP4/AM43xx

Add omap-des driver with platform data for OMAP4/AM43xx. Support added for DES
ECB and CBC modes. Also add support for 3DES operation where 3 64-bit keys are
used to perform a DES encrypt-decrypt-encrypt (des3_ede) operation on a buffer.

Tests have been conducted with the CRYPTO test manager, and functionality is
verified at different page length alignments.
Signed-off-by: Joel Fernandes <joelf@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>