usb: dwc3: qcom: Replace <linux/clk-provider.h> by <linux/of_clk.h>

The DWC3 USB driver is not a clock provider, and just needs to call
of_clk_get_parent_count().

Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.

Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Felipe Balbi <balbi@kernel.org>