crypto: caam - make CAAM_PTR_SZ dynamic

In order to be able to configure CAAM pointer size at run-time, which
needed to support i.MX8MQ, which is 64-bit SoC with 32-bit pointer
size, convert CAAM_PTR_SZ to refer to a global variable of the same
name ("caam_ptr_sz") and adjust the rest of the code accordingly. 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>