r8152: spilt rtl_set_eee_plus and r8153b_green_en

commit 40fa7568

 upstream.

Add rtl_eee_plus_en() and rtl_green_en().

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>