dt-bindings: imx: add clock bindings for i.MX8MN GPT

The i.MX8MN has a General Purpose Timer (GPT) just like the i.MX8MM,
which already has such bindings. Add the relevant bindings for the Nano
SoC too.
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Link: https://lore.kernel.org/r/20220317223600.175894-1-alvin@pqrs.dkSigned-off-by: Abel Vesa <abel.vesa@nxp.com>

include/dt-bindings/clock/imx8mn-clock.h

@@ -243,6 +243,20 @@
 
 #define IMX8MN_CLK_M7_CORE			221
 
-#define IMX8MN_CLK_END				222
+#define IMX8MN_CLK_GPT_3M			222
+#define IMX8MN_CLK_GPT1				223
+#define IMX8MN_CLK_GPT1_ROOT			224
+#define IMX8MN_CLK_GPT2				225
+#define IMX8MN_CLK_GPT2_ROOT			226
+#define IMX8MN_CLK_GPT3				227
+#define IMX8MN_CLK_GPT3_ROOT			228
+#define IMX8MN_CLK_GPT4				229
+#define IMX8MN_CLK_GPT4_ROOT			230
+#define IMX8MN_CLK_GPT5				231
+#define IMX8MN_CLK_GPT5_ROOT			232
+#define IMX8MN_CLK_GPT6				233
+#define IMX8MN_CLK_GPT6_ROOT			234
+
+#define IMX8MN_CLK_END				235
 
 #endif