V4L/DVB (7598): em28xx: several fixes on gpio programming

em28xx-cards.c:
 - Fix reversed val/rst values in both analog_gpio and digital_gpio
   vectors
 - Fix crash that would was occurring during every analog startup
   while looping over gpio_ctl
 - Remove what appears to be a redundant setting of gpio_ctl->val
 - Don't use OREN538 demodulation for the HVR-950 (prevents ATSC
   scanning from working)

em28xx-dvb.c:
 - Tuner should be in digital mode when issuing the reset
 - Add copyright
 - Change struct definition (corresponds to fix in em28xx-cards.c for
   gpio_ctl looping)

Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>