f_gsi: Replace == check against SUPER_SPEED to >=

There is no difference in terms of supporting USB function suspend and
resume functionality between USB super speed and super speed plus. Hence
replace == check against SUPER_SPEED to >= to enable all functionality
supported with super speed to super speed plus.

Change-Id: I6226943b60e79bbb1504b2739965a5a2ff5f2a35
Signed-off-by: Mayank Rana <mrana@codeaurora.org>