nvec_keyboard:Correcting Virtual code for Escape Key

On LDK there is no .kl file refered for keyboard.
In code_tab_102us array corrected the Virtual code for Escape Key.
From linux/input.h key 1 is KEY_ESC and not KEY_BACK
Verified on LDK with firefox.

Bug 684439

Change-Id: If52980f8c405ab96036778e9c3615ca76626c451
Reviewed-on: http://git-master/r/1914
Tested-by: Sachin Nikam <snikam@nvidia.com>
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Sachin Nikam <snikam@nvidia.com>
Reviewed-by: Gary King <gking@nvidia.com>
diff --git a/drivers/input/keyboard/tegra-nvec.c b/drivers/input/keyboard/tegra-nvec.c
index 9572a7f..883b1c7 100644
--- a/drivers/input/keyboard/tegra-nvec.c
+++ b/drivers/input/keyboard/tegra-nvec.c
@@ -55,7 +55,7 @@
  */
 NvU8 code_tab_102us[EC_TOTAL_CODES] = {
 	KEY_GRAVE,	// 0x00
-	KEY_BACK,
+	KEY_ESC,
 	KEY_1,
 	KEY_2,
 	KEY_3,