drm/panel: mantix: Improve power off sequence

drm/panel: mantix: Improve power off sequence

According to the sequence from section 7.3.4 of FT8006P datasheet,
TP_RSTN and RESX should be asserted after disabling AVDD and AVEE and
together with VDDI.

Also, AVEE power down needs to happen at least 150ms after entering
sleep mode.

Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260105-mantix-halo-fixes-v1-3-1ebc9b195a34@puri.sm