drm/bridge: synopsys: dw-mipi-dsi: enable EoTp by default

Enable the transmission of an EoTp (end of transmission packet) by
default. EoTp should be enabled anyway because it is a Linux necessity
that can be disabled by a dsi mod_flag if needed.

EoTp signals the end of an HS transmission, this adds overall robustness
at protocol level at the expense of an increased overhead.

Signed-off-by: Christoph Fritz <chf.fritz@googlemail.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/6a7293bd06942131161c5a7b7878c51cfbbb807e.camel@googlemail.com