[media] media/usb/gspca: Add support for Scopium astro webcam (0547:7303)

This patch does not modify existing drivers. It adds subdriver
to gspca for DTCS033 (Scopium) webcam for astrophotography.
The patch adds dtcs033.c and modifies Kconfig and Makefile.

Signed-off-by: Robert Butora <robert.butora.fi@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>