linux-wandboard

tee: add forward declaration for struct device

tee_drv.h references struct device, but does not include device.h nor
platform_device.h. Therefore, if tee_drv.h is included by some file
that does not pull device.h nor platform_device.h beforehand, we have a
compile warning. Fix this by adding a forward declaration.

Submitted upstream, see link below.

Link: http://lists.infradead.org/pipermail/linux-arm-kernel/2017-May/509790.html
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Joakim Bech <joakim.bech@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
(cherry picked from commit 2e26af92fd860371fd65a2c16306cce4508285a1)