[media] em28xx: reduce the polling interval for GPI connected buttons

For GPI-connected buttons without (hardware) debouncing, the polling interval
needs to be reduced to detect button presses properly.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --cc drivers/media/usb/em28xx/em28xx-input.c
Simple merge

diff --cc drivers/media/usb/em28xx/em28xx.h
Simple merge