usb: renesas: gadget: use generic map/unmap routines
usb: renesas: gadget: use generic map/unmap routines

those routines have everything we need to map/unmap
USB requests and it's better to use them.

Tested-by: Kuninori Morimoto <a3b51ccb87d18302c1692defcfbf83319d1737eb@renesas.com>
Signed-off-by: Felipe Balbi <94dddeeef08b001e003cce128ddc162a4e2c6cd2@ti.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs