usb: chipidea: add CI_HDRC_HAS_SHORT_PKT_LIMIT flag

Currently, the imx deivice controller has below limitations:

1. can't generate short packet interrupt if IOC not set in dTD. So if one
request span more than one dTDs and only the last dTD set IOC, the usb
request will pending there if no more data comes.
2. the controller can't accurately deliver data to differtent usb requests
in some cases due to short packet. For example: one usb request span 3
dTDs, then if the controller received a short packet the next packet
will go to 2nd dTD of current request rather than the first dTD of next
request.
3. can't build a bus packet use multiple dTDs. For example: controller
needs to send one packet of 512 bytes use dTD1 (200 bytes) + dTD2
(312 bytes), actually the host side will see 200 bytes short packet.

Based on these limits, add CI_HDRC_HAS_SHORT_PKT_LIMIT flag and use it on
imx platforms.

Signed-off-by: Xu Yang <[e-mail]>
Acked-by: Peter Chen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/chipidea/ci.h

···
 	bool				b_sess_valid_event;
 	bool				imx28_write_fix;
 	bool				has_portsc_pec_bug;
+	bool				has_short_pkt_limit;
 	bool				supports_runtime_pm;
 	bool				in_lpm;
 	bool				wakeup_int;

drivers/usb/chipidea/ci_hdrc_imx.c

···
 	struct ci_hdrc_platform_data pdata = {
 		.name		= dev_name(&pdev->dev),
 		.capoffset	= DEF_CAPOFFSET,
+		.flags		= CI_HDRC_HAS_SHORT_PKT_LIMIT,
 		.notify_event	= ci_hdrc_imx_notify_event,
 	};
 	int ret;

drivers/usb/chipidea/core.c

···
 		CI_HDRC_SUPPORTS_RUNTIME_PM);
 	ci->has_portsc_pec_bug = !!(ci->platdata->flags &
 		CI_HDRC_HAS_PORTSC_PEC_MISSED);
+	ci->has_short_pkt_limit = !!(ci->platdata->flags &
+		CI_HDRC_HAS_SHORT_PKT_LIMIT);
 	platform_set_drvdata(pdev, ci);
 
 	ret = hw_device_init(ci, base);

include/linux/usb/chipidea.h

···
 #define CI_HDRC_PHY_VBUS_CONTROL	BIT(16)
 #define CI_HDRC_HAS_PORTSC_PEC_MISSED	BIT(17)
 #define CI_HDRC_FORCE_VBUS_ACTIVE_ALWAYS	BIT(18)
+#define	CI_HDRC_HAS_SHORT_PKT_LIMIT	BIT(19)
 	enum usb_dr_mode	dr_mode;
 #define CI_HDRC_CONTROLLER_RESET_EVENT		0
 #define CI_HDRC_CONTROLLER_STOPPED_EVENT	1