RISC-V: Fix gas configure support for riscv*-*-*.

gas/
	* configure.tgt (riscv*): Accept as alias for riscv32*.

gas/ChangeLog

@@ -1,3 +1,7 @@
+2018-07-27  Jim Wilson  <jimw@sifive.com>
+
+	* configure.tgt (riscv*): Accept as alias for riscv32*.
+
 2018-07-26  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR gas/23453

gas/configure.tgt

@@ -89,8 +89,8 @@ case ${cpu} in
   pj*)			cpu_type=pj endian=big ;;
   powerpc*le*)		cpu_type=ppc endian=little ;;
   powerpc*)		cpu_type=ppc endian=big ;;
-  riscv32*)		cpu_type=riscv endian=little arch=riscv32 ;;
   riscv64*)		cpu_type=riscv endian=little arch=riscv64 ;;
+  riscv32* | riscv*)	cpu_type=riscv endian=little arch=riscv32 ;;
   rs6000*)		cpu_type=ppc ;;
   rl78*)		cpu_type=rl78 ;;
   rx)			cpu_type=rx ;;