iwlwifi: dbg: fill radio registers data regardless of fifos data dumping

The driver calculates memory regions dump size, allocate memory and
fills the data.  The driver fills the radio registers data only if the
memory size of the fifos is greater then zero, so in case the user
masked out the fifos from the dump, the driver will skip filling the
radio register data.

Solve this by checking filling radio registers data independently from
fifos data.

Signed-off-by: Shahar S Matityahu <shahar.s.matityahu@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>