crypto: atmel-aes - create sections to regroup functions by usage

This patch only creates sections to regroup functions by usage.
This will help to integrate the GCM support patch later by making the
difference between shared/common and specific code. Hence current
sections are:

- Shared functions: common code which will be reused by the GCM support.
- CPU transfer: handles transfers monitored by the CPU (PIO accesses).
- DMA transfer: handles transfers monitored by the DMA controller.
- AES async block ciphers: dedicated to the already supported block ciphers
- Probe functions: used to register all crypto algorithms.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>