usb: composite: Move bitmap related operations to ./include/linux/bitmap.h

The BITMAP related operations can now be moved to ./include/linux/bitmap.h
file to mimic the Linux kernel directory tree.

This change also allows to remove the lin_gadget_compat.h header file
(which is a legacy code only for composite U-boot layer).
It was also possible to remove #includes from several USB gadget drivers.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Stefan Agner <stefan.agner@toradex.com>

include/linux/bitmap.h

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0+
+#ifndef __LINUX_BITMAP_H
+#define __LINUX_BITMAP_H
+
+#include <asm/types.h>
+#include <linux/types.h>
+#include <linux/bitops.h>
+
+#define small_const_nbits(nbits) \
+	(__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
+
+static inline void bitmap_zero(unsigned long *dst, int nbits)
+{
+	if (small_const_nbits(nbits)) {
+		*dst = 0UL;
+	} else {
+		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+
+		memset(dst, 0, len);
+	}
+}
+
+#endif /* __LINUX_BITMAP_H */

include/linux/types.h

@@ -158,4 +158,7 @@ struct ustat {
 	char			f_fpack[6];
 };
 
+#define DECLARE_BITMAP(name, bits) \
+	unsigned long name[BITS_TO_LONGS(bits)]
+
 #endif /* _LINUX_TYPES_H */

include/linux/usb/composite.h

@@ -24,7 +24,7 @@
 #include <common.h>
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
-#include <usb/lin_gadget_compat.h>
+#include <linux/bitmap.h>
 
 /*
  * USB function drivers should return USB_GADGET_DELAYED_STATUS if they