BACKPORT: FROMLIST: usb: dwc3: Set SUSPENDENABLE soon after phy init

After phy initialization, some phy operations can only be executed while
in lower P states. Ensure GUSB3PIPECTL.SUSPENDENABLE and
GUSB2PHYCFG.SUSPHY are set soon after initialization to avoid blocking
phy ops.

Previously the SUSPENDENABLE bits are only set after the controller
initialization, which may not happen right away if there's no gadget
driver or xhci driver bound. Revise this to clear SUSPENDENABLE bits
only when there's mode switching (change in GCTL.PRTCAPDIR).

Fixes: 6d735722 ("usb: dwc3: core: Prevent phy suspend during init")
Cc: stable@vger.kernel.org
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Bug: 374242909
Bug: 359966146
Test: gadget enumeration
Link: https://lore.kernel.org/linux-usb/633aef0afee7d56d2316f7cc3e1b2a6d518a8cc9.1738280911.git.Thinh.Nguyen@synopsys.com/


Change-Id: Ib2cb7c6f0f5c7082fa18155403633e36f589ebbc
Signed-off-by: Roy Luo <royluo@google.com>