Input: tegra-kbc - allocate pdata before using it

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

   commit 023cea0e
   Author: Shridhar Rasal <srasal@nvidia.com>
   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: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/tegra-kbc.c

@@ -630,6 +630,7 @@ tegra_kbc_dt_parse_pdata(struct platform_device *pdev)
 	if (!np)
 		return NULL;
 
+	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return NULL;