staging: rtl8192e: Remove entry .tx_enable from struct rtl819x_ops

Remove entry .tx_enable and replace it with function name
rtl92e_enable_tx. This increases readability of the code.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/76955e787fd161dea83d10e81054fafb3b334b5c.1677010997.git.philipp.g.hortmann@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>