Update my email address.

I've left SiFive and have a new gmail account because it is convenient
to use with git send-email.  I'm planning to use this for my RISC-V
work.  My tuliptree address still works, it just isn't as convenient.

	binutils:
	* MAINTAINERS (RISC-V): Update my address.

binutils/MAINTAINERS

@@ -124,7 +124,7 @@ responsibility among the other maintainers.
   PPC vector ext   Aldy Hernandez <aldyh@redhat.com>
   RISC-V	   Palmer Dabbelt <palmer@dabbelt.com>
   RISC-V	   Andrew Waterman <andrew@sifive.com>
-  RISC-V	   Jim Wilson <jimw@sifive.com>
+  RISC-V	   Jim Wilson <jim.wilson.gcc@gmail.com>
   RISC-V	   Nelson Chu <nelson.chu@sifive.com>
   RX               Nick Clifton <nickc@redhat.com>
   S12Z		   John Darrington <john@darrington.wattle.id.au>