.mailmap: map Ruchika Gupta's mail address

Freescale mail addresses are not valid anymore.

Reported-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

.mailmap

@@ -36,6 +36,7 @@ Prabhakar Kushwaha <prabhakar@freescale.com>
 Rajeshwari Shinde <rajeshwari.s@samsung.com>
 Ricardo Ribalda <ricardo@ribalda.com> <ricardo.ribalda@uam.es>
 Ricardo Ribalda <ricardo@ribalda.com> <ricardo.ribalda@gmail.com>
+Ruchika Gupta <ruchika.gupta@nxp.com> <ruchika.gupta@freescale.com>
 Sandeep Paulraj <s-paulraj@ti.com>
 Shaohui Xie <Shaohui.Xie@freescale.com>
 Stefan Roese <stroese>