staging: pi433: fix CamelCase for Ohm identifiers

Fixes checkpatch warnings:

  CHECK: Avoid CamelCase: <fiftyOhm>
  CHECK: Avoid CamelCase: <twohundretOhm>

Signed-off-by: Valentin Vidic <Valentin.Vidic@CARNet.hr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>