usb: dwc3: remove unused sg struct member

usb: dwc3: remove unused sg struct member

The sg (scatter-gather list pointer) member of the dwc3_request struct
is no longer used and should be removed. This patch eliminates the unused
member, cleaning up the struct.

This change improves code clarity and avoids maintaining unnecessary
members in the structure.

Reviewed-by: Ricardo B. Marliere <rbm@suse.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20241118194006.77c7b126@canb.auug.org.au/
Signed-off-by: Luis Felipe Hernandez <luis.hernandez093@gmail.com>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20241120154604.51815-1-luis.hernandez093@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>