drm/msm/disp/dpu1: add helper to know if display is builtin

Since DRM encoder type for few encoders can be similar
(like eDP and DP), get the connector type for a given
encoder to differentiate between builtin and pluggable
displays.

Changes in v1:
- add connector type in the disp_info (Dmitry)
- add helper functions to know encoder type
- update commit text reflecting the change

Changes in v2:
- avoid hardcode of connector type for DSI as it may not be true (Dmitry)
- get the HPD information from encoder bridge

Changes in v3:
- use connector type instead of bridge ops in determining
connector (Dmitry)

Changes in v4:
- get type from the drm connector rather from bridge connector (Dmitry)

Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/512356/
Link: https://lore.kernel.org/r/1669021695-4397-3-git-send-email-quic_kalyant@quicinc.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>