[media] gspca-stk1135: Add delay after configuring clock

Add a small delay at the end of configure_clock() to allow sensor to initialize.
This is needed by Asus VX2S laptop webcam to detect sensor type properly (the already-supported MT9M112).

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>