arm: tegra: e2171: use push pull for max77620 gpio7

arm: tegra: e2171: use push pull for max77620 gpio7

Open drain mode can not make the load swich TPS22908
connected to max77620 gpio7 work properly. It's needed
to be configured as push pull mode.

Change-Id: I195834e23fa703bdd0548a03864c6e6bac696caa
Signed-off-by: Kerwin Wan <kerwinw@nvidia.com>
Reviewed-on: http://git-master/r/427752
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Laxman Dewangan <ldewangan@nvidia.com>