Revert "Remove remainders of HPPA backend"

This reverts commit d41f3c3cc7a5fb9de144cc4022da14a9ff010671.

Signed-off-by: Richard Henderson <rth@twiddle.net>
diff --git a/configure b/configure
index 17d52cd..494c9cc 100755
--- a/configure
+++ b/configure
@@ -510,6 +510,8 @@
   cpu="arm"
 elif check_define __aarch64__ ; then
   cpu="aarch64"
+elif check_define __hppa__ ; then
+  cpu="hppa"
 else
   cpu=$(uname -m)
 fi
@@ -6107,6 +6109,9 @@
   cris)
     disas_config "CRIS"
   ;;
+  hppa)
+    disas_config "HPPA"
+  ;;
   i386|x86_64|x32)
     disas_config "I386"
   ;;