usb: dwc2: gadget: Final fixes for BDMA ISOC

Done fixes and tested hsotg gadget's BDMA mode. Tested Control,
Bulk, Isoc, Inter transfers. Added code for isoc transfers,
removed unusable code, done minor fixes. Affected functions
and IRQ handlers:
- dwc2_hsotg_start_req(),
- dwc2_hsotg_ep_enable(),
- dwc2_hsotg_ep_queue(),
- dwc2_hsotg_handle_outdone(),
- GINTSTS_GOUTNAKEFF handler,

Removed 'has_correct_parity' flag from 'dwc2_hsotg_ep' struct.
Before this patch series, to set the data pid the DWC2 gadget
driver was toggling the even/odd until it match, then were
leaving it set. But now I have added mechanism to set pid and
excluded all code where this flag was set.

Tested-by: John Keeping <john@metanate.com>
Signed-off-by: Vardan Mikayelyan <mvardan@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/hw.h

@@ -560,6 +560,7 @@
 #define DXEPINT_INEPNAKEFF		(1 << 6)
 #define DXEPINT_BACK2BACKSETUP		(1 << 6)
 #define DXEPINT_INTKNEPMIS		(1 << 5)
+#define DXEPINT_STSPHSERCVD		(1 << 5)
 #define DXEPINT_INTKNTXFEMP		(1 << 4)
 #define DXEPINT_OUTTKNEPDIS		(1 << 4)
 #define DXEPINT_TIMEOUT			(1 << 3)