Support building Asterisk for Raspberry Pi/Raspbian with hard-float support

Building Asterisk on Raspbian with hard-float support fails as it uses the
string 'linux-gnueabihf' for host os, as opposed to 'linux-gnueabi'. This patch
modifies the configure script for Asterisk such that it will match on any
string beginning with 'linux-gnueabi', as opposed to requiring an explicit
match.

(closes issue ASTERISK-21006)
Reported by: Christian Hesse
Tested by: Christian Hesse
patches:
  linux-gnueabihf.patch uploaded by Christian Hesse (license 6459)
  linux-gnueabihf-autoconf.patch uploaded by Christian Hesse (license 6459)
........

Merged revisions 380520 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 380521 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@380522 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configure.ac

@@ -178,7 +178,7 @@ case "${host_os}" in
      OSARCH=cygwin
      PBX_WINARCH=1
      ;;
-     linux-gnueabi)
+     linux-gnueabi*)
      OSARCH=linux-gnu
      ;;
      kfreebsd*-gnu)