sunxi: hardware-feature-specific function index defines for PORT F UART0

Commit 487b3277 ("sunxi: GPIO pin mux hardware-feature-specific function
index defines") renamed all GPIO index defines, but missed the PORT F
UART0 setup functions.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>