usb: musb: gadget: fix dma length in txstate

DMA length should not go beyond the availabe space
of request buffer, so fix it.

Also set max_len of cppi dma channel as max size of
int type, so make musb dma handling happier.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Anand Gadiyar <gadiyar@ti.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/musb/cppi_dma.c b/drivers/usb/musb/cppi_dma.c
index 59dc3d3..5ab5bb8 100644
--- a/drivers/usb/musb/cppi_dma.c
+++ b/drivers/usb/musb/cppi_dma.c
@@ -322,6 +322,7 @@
 				index, transmit ? 'T' : 'R', cppi_ch);
 	cppi_ch->hw_ep = ep;
 	cppi_ch->channel.status = MUSB_DMA_STATUS_FREE;
+	cppi_ch->channel.max_len = 0x7fffffff;
 
 	DBG(4, "Allocate CPPI%d %cX\n", index, transmit ? 'T' : 'R');
 	return &cppi_ch->channel;