USB: usbtmc: Add flag rigol_quirk to usbtmc_device_data
These patches implement a modification of the USBTMC
protocol to allow operation with Rigol equipment. Rigol requires that a
single TMC request to receive any buffer size and bulk requests to get the
data. The original algorithm sends a TMC request for each subset of the data
(a single USB transaction). The modification is only active for Rigol
equipment, vendor and product set is contained in the array usbtmc_id_quirk.
This patch creates the rigol_quirk variable and the arrays for the
idvendor and idproduct.