Add custom pinfunc macros

Ported from seco-ne/kernel/linux-imx-kuk!126 (a3e8d2e7)

arch/arm64/boot/dts/seco/include/imx8mm-pinfunc.h

@@ -6,6 +6,15 @@
 #ifndef __DTS_IMX8MM_PINFUNC_H
 #define __DTS_IMX8MM_PINFUNC_H
 
+#define MX8MM_IOMUXC_PULLUP_ENABLE   0x140
+#define MX8MM_IOMUXC_PULLDOWN_ENABLE 0x100
+#define MX8MM_IOMUXC_HYS             0x080
+#define MX8MM_IOMUXC_OPEN_DRAIN      0x020
+#define MX8MM_IOMUXC_SLEW(a)        (((a)&0x03)<<3)
+#define MX8MM_IOMUXC_FAST            0x010
+#define MX8MM_IOMUXC_SLOW            0x008
+#define MX8MM_IOMUXC_DRIVE(a)       ((a)&0x7)
+
 /*
  * The pin function ID is a tuple of
  * <mux_reg conf_reg input_reg mux_mode input_val>