[media] IR: ene_ir: few bugfixes

This is a result of last round of debug with
Sami R <maesesami@gmail.com>.

Thank you Sami very much!

The biggest bug I fixed is that,
I was clobbering the CIRCFG register after it is setup
That wasn't a good idea really

And some small refactoring, etc.

Tested-by: Sami R <maesesami@gmail.com>
Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>