usb: dwc3: Remove used delay for QMP PHY specific initialization

Currently cumulative delay of 300ms is being added as part QMP PHY
specific initialization sequeunce. This delay is not required as
part of this initialization and it doesn't affect the functionality
of QMP PHY. Hence remove this delay which would improve device
boot up time.

Change-Id: I69d182ab14078f7d4c779bf9f57b93d1c4e8649d
Signed-off-by: Mayank Rana <mrana@codeaurora.org>