staging: rtl8192e: Remove priv->rf_chip

priv->rf_chip is initialized to RF_8256 and not used. Remove
initialization, variable and enum as it is dead code.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/2ce85c1a159ae376d82c19c61e694924f07d1093.1679732276.git.philipp.g.hortmann@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>