Enable accelerated AES-XTS software crypto in GENERIC.

In particular, using GELI on a root filesystem will only use
accelerated software crypto drivers if they are available before the
root filesystem is mounted.  While these modules can be loaded from
the loader, including them in GENERIC provides a better out-of-the-box
experience for users.

Both aesni(4) and armv8crypto(4) provide accelerated implementations
of the default cipher used by GELI (AES-XTS) in addition to other
ciphers.

Reviewed by:	mhorne, allanjude, markj
Differential Revision:	https://reviews.freebsd.org/D28100

sys/amd64/conf/GENERIC

@@ -315,6 +315,7 @@ device		wpi			# Intel 3945ABG wireless NICs.
 
 # Pseudo devices.
 device		crypto			# core crypto support
+device		aesni			# AES-NI OpenCrypto module
 device		loop			# Network loopback
 device		padlock_rng		# VIA Padlock RNG
 device		rdrand_rng		# Intel Bull Mountain RNG

sys/arm64/conf/GENERIC

@@ -217,6 +217,7 @@ device		aw_rtc		# Allwinner Real-time Clock
 device		mv_rtc		# Marvell Real-time Clock
 
 # Crypto accelerators
+device		armv8crypto	# ARMv8 OpenCrypto module
 device		safexcel	# Inside Secure EIP-97
 
 # Watchdog controllers

sys/i386/conf/GENERIC

@@ -287,6 +287,7 @@ device		wpi			# Intel 3945ABG wireless NICs.
 
 # Pseudo devices.
 device		crypto			# core crypto support
+device		aesni			# AES-NI OpenCrypto module
 device		loop			# Network loopback
 device		padlock_rng		# VIA Padlock RNG
 device		rdrand_rng		# Intel Bull Mountain RNG