uboot-imx

usb:gadget:Remove redundant #includes for USB composite gadget and its functions

Only the <linux/usb/gadget.h> requires error.h include. Hence, several
includes of error.h at USB gadget functions are not needed.

Moreover unnecessary malloc.h includes were also removed.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Cc: Marek Vasut <marex@denx.de>