Update ARMv7's release build process to build kernels and ramdisks

per SoC.  It's heavily based on the SGI port.
ok florian@

src/etc/etc.armv7/Makefile.inc

@@ -1,6 +1,15 @@
-#	$OpenBSD: Makefile.inc,v 1.1 2013/09/04 16:53:40 patrick Exp $
+#	$OpenBSD: Makefile.inc,v 1.2 2013/09/07 23:04:44 patrick Exp $
+
+ALLSOC=IMX OMAP
+KERNELS=
+MDEXT=
+
+.for SOC in ${ALLSOC}
+KERNELS+=	GENERIC-${SOC} bsd.${SOC}
+MDEXT+=		bsd.rd.${SOC}
+.endfor
 
 bootblocks:
 
-MDEXT=	bsd.rd miniroot-am335x-${OSrev}.fs miniroot-beagle-${OSrev}.fs \
+MDEXT+=	miniroot-am335x-${OSrev}.fs miniroot-beagle-${OSrev}.fs \
 	miniroot-panda-${OSrev}.fs