dt-bindings: clocks: imx8mp: Add ID for usb suspend clock

usb suspend clock has a gate shared with usb_root_clk.

Fixes: 9c140d99 ("clk: imx: Add support for i.MX8MP clock driver")
Cc: stable@vger.kernel.org # v5.19+
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/1664549663-20364-1-git-send-email-jun.li@nxp.com

include/dt-bindings/clock/imx8mp-clock.h

@@ -324,8 +324,9 @@
 #define IMX8MP_CLK_CLKOUT2_SEL			317
 #define IMX8MP_CLK_CLKOUT2_DIV			318
 #define IMX8MP_CLK_CLKOUT2			319
+#define IMX8MP_CLK_USB_SUSP			320
 
-#define IMX8MP_CLK_END				320
+#define IMX8MP_CLK_END				321
 
 #define IMX8MP_CLK_AUDIOMIX_SAI1_IPG		0
 #define IMX8MP_CLK_AUDIOMIX_SAI1_MCLK1		1