crypto/caam_jr: fix const pointer in UIO filename parsing

crypto/caam_jr: fix const pointer in UIO filename parsing

With latest glibc (Fedora Rawhide):
../drivers/crypto/caam_jr/caam_jr_uio.c: In function
	'file_name_match_extract':
../drivers/crypto/caam_jr/caam_jr_uio.c:111:16: warning: assignment
	discards 'const' qualifier from pointer target type
	[-Wdiscarded-qualifiers]
  111 |         substr = strstr(filename, match);
      |                ^

Fixes: e7a45f3cc245 ("crypto/caam_jr: add UIO specific operations")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>