crypto: qat - Constify struct pm_status_row

'struct pm_status_row' are not modified in this driver.

Constifying this structure moves some data to a read-only section, so
increases overall security.

Update the prototype of some functions accordingly.

On a x86_64, with allmodconfig, as an example:
Before:
======
   text	   data	    bss	    dec	    hex	filename
   4400	   1059	      0	   5459	   1553	drivers/crypto/intel/qat/qat_common/adf_gen4_pm_debugfs.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
   5216	    243	      0	   5459	   1553	drivers/crypto/intel/qat/qat_common/adf_gen4_pm_debugfs.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>