drm/arcpgu: Really delete file

Somehow this got forgotten when I applied the patch in

commit e2c406e
Author: Daniel Vetter <[email protected]>
Date:   Tue Jan 12 09:43:54 2021 +0100

    drm/arc: Inline arcpgu_crtc.c

Fixes: e2c406e ("drm/arc: Inline arcpgu_crtc.c")
Cc: Thomas Zimmermann <[email protected]>
Cc: Eugeniy Paltsev <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Alexey Brodkin <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Signed-off-by: Thomas Zimmermann <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: danvet