usb: Add 1ms delay after first Get Descriptor request

Logitech Unifying Receiver 046d:c52b bcdDevice 12.10 seems
sensitive about the first Get Descriptor request. If there
are any other requests in the same microframe, the device
reports bogus data, first of the descriptor parts is not
sent to the host. Wait over one microframe duration before
issuing subsequent requests to avoid probe failure with
this device, since it can be used to connect USB keyboards.

Signed-off-by: Marek Vasut <marex@denx.de>
Tested-by: Janne Grunau <j@jannau.net>