drivers/cmsis_dap: use blocking flag instead of wait timeout

drivers/cmsis_dap: use blocking flag instead of wait timeout

CMSIS-DAP bulk backend read op used two timeouts: transfer timeout
used in libusb_fill_bulk_transfer() and wait timeout used optionally
in libusb_handle_events_timeout_completed().

The real usage is limited to two cases only:
1) blocking read: the same timeout is used for both transfer
and wait
2) non-blocking read: transfer timeout is used in
libusb_fill_bulk_transfer(),
libusb_handle_events_timeout_completed() is called with zero timeout.

Use blocking flag as read op parameter to distinguish between
these two cases.

See also [1]

Link: [1] 8596: jtag: cmsis_dap: include helper/time_support.h | https://review.openocd.org/c/openocd/+/8596
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Change-Id: Ia755f17dc72bb9ce8e02065fee6a064f8eec6661
Reviewed-on: https://review.openocd.org/c/openocd/+/8639
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>