clk: sunxi: Demote non-conformant kernel-doc headers

Headers must describe their parameters.

Fixes the following W=1 kernel build warning(s):

 drivers/clk/sunxi/clk-sun9i-core.c:27: warning: Function parameter or member 'req' not described in 'sun9i_a80_get_pll4_factors'
 drivers/clk/sunxi/clk-sun9i-core.c:100: warning: Function parameter or member 'req' not described in 'sun9i_a80_get_gt_factors'
 drivers/clk/sunxi/clk-sun9i-core.c:155: warning: Function parameter or member 'req' not described in 'sun9i_a80_get_ahb_factors'
 drivers/clk/sunxi/clk-sun9i-core.c:235: warning: Function parameter or member 'req' not described in 'sun9i_a80_get_apb1_factors'
 drivers/clk/sunxi/clk-usb.c:22: warning: cannot understand function prototype: 'struct usb_reset_data '
 drivers/clk/sunxi/clk-sun6i-ar100.c:26: warning: Function parameter or member 'req' not described in 'sun6i_get_ar100_factors'

Cc: "Emilio López" <emilio@elopez.com.ar>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: Boris BREZILLON <boris.brezillon@free-electrons.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210303142430.3168703-1-lee.jones@linaro.org