drm/exynos: exynos7_drm_decon: remove ctx->suspended

Condition guards are found to be redundant, as the call flow is properly
managed now, as also observed in the Exynos5433 DECON driver. Since
state checking is no longer necessary, remove it.

This also fixes an issue which prevented decon_commit() from
decon_atomic_enable() due to an incorrect state change setting.

Fixes: 96976c3d ("drm/exynos: Add DECON driver")
Cc: stable@vger.kernel.org
Suggested-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>