drm/msm/dpu: move intf and wb assignment to dpu_encoder_setup_display()

drm/msm/dpu: move intf and wb assignment to dpu_encoder_setup_display()

intf and wb resources are not dependent on the rm global
state so need not be allocated during dpu_encoder_virt_atomic_mode_set().

Move the allocation of intf and wb resources to dpu_encoder_setup_display()
so that we can utilize the hw caps even during atomic_check() phase.

Since dpu_encoder_setup_display() already has protection against
setting invalid intf_idx and wb_idx, these checks can now
be dropped as well.

changes in v2:
	- add phys->hw_intf and phys->hw_wb checks back

changes in v3:
	- correct the Fixes tag

Fixes: e02a559a720f ("drm/msm/dpu: make changes to dpu_encoder to support virtual encoder")
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/489885/
Link: https://lore.kernel.org/r/1655406084-17407-1-git-send-email-quic_abhinavk@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>