usb: otg: Increase delay for asserting controller reset

This change increases delay from 10 usecs, which is
the min value recommended by HW designers, to 100 usecs.
This is required since in some cases, using the minimal
value proved not to reset the controller correctly to POR
registers values.

Change-Id: I192e12ac0c750b37d04ce494ba7a6a23eea7164d
Signed-off-by: Amit Blay <ablay@codeaurora.org>