staging: r8188eu: ExternalPA is read-only

The variable ExternalPA in struct hal_data_8188e is never set.
It stays at the default value 0. Remove it and remove related
dead code.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220201084259.7497-2-straube.linux@gmail.com


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