crypto/aesni_gcm: check dependency version with make

crypto/aesni_gcm: check dependency version with make

The aesni_mb driver has a check in its Makefile for the correct version of
the IPsec_MB library, but this check was missed for the aesni_gcm driver.
Add this check to the makefile, removing an unnecessary assignment in the
process.

Suggested-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>