Translate OpenBSD architecture name to the name used by upstream.

Index: configure
--- configure.orig
+++ configure
@@ -36,13 +36,30 @@ if host.startswith('sparc') or host.startswith('sun'):
 
 makefile = ''
 
+
+# Some OpenBSD architecture names don't match the
+# architecture name used by upstream, so they require to
+# be translated, so they can be recognized by build scripts.
+#
+def translate_arch(openbsd_arch):
+  archs = {
+    'arm': 'arm32',
+    'armv7': 'arm32',
+    'i386': 'x86',
+    'powerpc64': 'ppc64',
+    'macppc': 'ppc32',
+    'powerpc': 'ppc32',
+  }
+  return archs.get(openbsd_arch, openbsd_arch)
+
+
 for arg in sys.argv[1:]:
   if arg.startswith('--prefix='):
     prefix = arg[9:]
     continue
   if arg.startswith('--host='):
     host = arg[7:]
-    host = host.split('-')[0]
+    host = translate_arch(host.split('-')[0])
     continue
   if arg.startswith('--soversion='):
     soversion = arg[12:]