drm/arc: Inline arcpgu_crtc.c

drm/arc: Inline arcpgu_crtc.c

Really not big anymore.

Note that we no longer clamp all errors to ENODEV, highlighted by Sam.

v2: Fixup update function, bug reported by Eugeniy

v3: Delete now unused crtc funcs (0day)

v4: Move encoder removal to right patch (Sam).

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210112084358.2771527-11-daniel.vetter@ffwll.ch