module: icp: rip out the Solaris loadable module architecture

After progressively folding away null cases, it turns out there's
/literally/ nothing there, even if some things are part of the
Solaris SPARC DDI/DKI or the seventeen module types (some doubled for
32-bit userland), or the entire modctl syscall definition.
Nothing.

Initialisation is handled in illumos-crypto.c,
which calls all the initialisers directly

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Attila Fülöp <attila@fueloep.org>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12895
Closes #12902

module/icp/io/aes.c

@@ -32,27 +32,10 @@
 #include <sys/crypto/spi.h>
 #include <sys/crypto/icp.h>
 #include <modes/modes.h>
-#include <sys/modctl.h>
 #define	_AES_IMPL
 #include <aes/aes_impl.h>
 #include <modes/gcm_impl.h>
 
-#define	CRYPTO_PROVIDER_NAME "aes"
-
-extern struct mod_ops mod_cryptoops;
-
-/*
- * Module linkage information for the kernel.
- */
-static struct modlcrypto modlcrypto = {
-	&mod_cryptoops,
-	"AES Kernel SW Provider"
-};
-
-static struct modlinkage modlinkage = {
-	MODREV_1, { (void *)&modlcrypto, NULL }
-};
-
 /*
  * Mechanism info structure passed to KCF during registration.
  */
@@ -199,20 +182,13 @@ static crypto_data_t null_crypto_data = { CRYPTO_DATA_RAW };
 int
 aes_mod_init(void)
 {
-	int ret;
-
 	/* Determine the fastest available implementation. */
 	aes_impl_init();
 	gcm_impl_init();
 
-	if ((ret = mod_install(&modlinkage)) != 0)
-		return (ret);
-
 	/* Register with KCF.  If the registration fails, remove the module. */
-	if (crypto_register_provider(&aes_prov_info, &aes_prov_handle)) {
-		(void) mod_remove(&modlinkage);
+	if (crypto_register_provider(&aes_prov_info, &aes_prov_handle))
 		return (EACCES);
-	}
 
 	return (0);
 }
@@ -228,7 +204,7 @@ aes_mod_fini(void)
 		aes_prov_handle = 0;
 	}
 
-	return (mod_remove(&modlinkage));
+	return (0);
 }
 
 static int