Input: tegra-kbc - allocate pdata before using it

Following commit broke DT support for tegra-kbc by removing pdata
allocation completely:

commit 023cea0ecfa2df034096c3f4afa796a0b2d1188a
Author: Shridhar Rasal <[e-mail]>
Date: Fri Feb 3 00:27:30 2012 -0800

Input: tegra-kbc - allow skipping setting up some of GPIO pins

This patch restores it.

Signed-off-by: Viresh Kumar <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/keyboard/tegra-kbc.c

···
 	if (!np)
 		return NULL;
 
+	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return NULL;