crypto: caam - move cpu_to_caam_dma() selection to runtime

Instead of selecting the implementation of
cpu_to_caam_dma()/caam_dma_to_cpu() at build time using the
preprocessor, convert the code to do that at run-time using IS_ENABLED
macro. This is needed to add support for i.MX8MQ. No functional change
intended.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Chris Spencer <christopher.spencer@sea.co.uk>
Cc: Cory Tusar <cory.tusar@zii.aero>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Horia Geantă <horia.geanta@nxp.com>
Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>