ARM: dts: msm: adjust virtual key map for msm8953 qrd

The virtual keys KEY_MENU/HOME/KEY_BACK are incorrectly defined
for msm8953 qrd. Exchange the positions of these three virtual
keys for a correct operation of the device.

Change-Id: I50bcfb7cbce775015c922553802663af9e81d3c2
Signed-off-by: Mao Li <maol@codeaurora.org>