usb: dwc3: fix dcache flush range calculation

usb: dwc3: fix dcache flush range calculation

The current flush operation will omit doing a flush/invalidate on
the first and last bytes if the base address and size are not aligned
with CACHELINE_SIZE.

This causes operation failures Qualcomm platforms.

Take in account the alignment and size of the buffer and also
flush the previous and last cacheline.

Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Marek Vasut <marex@denx.de>