omap3: pandora: Fix keypad keymap

The original TWL4030 keypad driver from linux-omap used KEY()
macro defined as (col, row), but while it was merged upstream
it was changed to use matrix keypad infrastructure, which uses
(row, col) format. Update the keymap in board file to match
layout of mainline driver.

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>