Turn on support for the Amazon "Elastic Network Adapter" in EC2 AMIs.

X-MFC-after:	318647 + fixes for some lock ordering warnings

release/Makefile.ec2

@@ -51,7 +51,7 @@ ec2ami: cw-ec2 ${CW_EC2_PORTINSTALL}
 	@echo "--------------------------------------------------------------"
 	@false
 .endif
-	/usr/local/bin/bsdec2-image-upload ${PUBLISH} --sriov \
+	/usr/local/bin/bsdec2-image-upload ${PUBLISH} --sriov --ena \
 	    ${.OBJDIR}/ec2.raw \
 	    "${TYPE} ${REVISION}-${BRANCH}-${TARGET}${AMINAMESUFFIX}" \
 	    "${TYPE} ${REVISION}-${BRANCH}-${TARGET}" \

release/tools/ec2.conf

@@ -78,6 +78,9 @@ vm_extra_pre_umount() {
 	# nodes, but apply the workaround just in case.
 	echo 'hw.broken_txfifo="1"' >> ${DESTDIR}/boot/loader.conf
 
+	# Load the kernel module for the Amazon "Elastic Network Adapter"
+	echo 'if_ena_load="YES"' >> ${DESTDIR}/boot/loader.conf
+
 	# The first time the AMI boots, the installed "first boot" scripts
 	# should be allowed to run:
 	# * ec2_configinit (download and process EC2 user-data)