[media] cx18-driver: fix handling of 'radio' module parameter

Reverse cx18-driver part of commit
90ab5ee9 and change
module_param_array() type from bool to int to fix
compiler warning:

In function ‘__check_radio’:
113:1: warning: return from incompatible pointer type [enabled by default]
At top level:
113:1: warning: initialization from incompatible pointer type [enabled by default]
113:1: warning: (near initialization for ‘__param_arr_radio.num’) [enabled by default]

v2: corrected version, don't change to module_param_named(), change
    all to int/uint

Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>