usb: musb: mediatek: Use clk_bulk API to simplify clock operations

This driver uses three clocks and there's no special handling, they're
either enabled or disabled sequentially: migrate to the clk_bulk API
to simplify clock handling.

This patch brings no functional changes.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220404145558.93340-1-angelogioacchino.delregno@collabora.com


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