This patch fixes a parameter mismatch bug when using the CKM_AES_GCM
mechanism. This bug also renames the 'generate_iv' option to
'aes_gcm_generate_iv' to reflect the fact that it only applies to
the CKM_AES_GCM mechanism since IVs will always be generated when
using CKM_AES_CBC.
Change-Id: Iaa94b5cf2b2f77aaed72ec6b8b11e5ccf1fc3cca