fc-shell TCH DL handler: add support for CSD modes TCH DL capture mechanism in FC Tourmaline firmware has been extended to support CSD modes in addition to speech - add the necessary support on the host tools side. It needs to be noted that this mechanism in its present state does NOT provide the debug utility value that was sought: as we learned only after the code was implemented, TI's DSP has a misfeature in that the buffer we are reading (a_dd_0[]) is zeroed out when the IDS block is enabled, i.e., we are reading all zeros and not the real DL bits we were after. But since the code has already been written, we are keeping it - perhaps we can do some tests with IDS disabled.

/*
 * For sizing our buffers etc in rvinterf, we need a limit on the size of
 * message packets we can send to the target.  As it happens, the packet
 * Rx code in RVT on the target side also has a limit (quite naturally,
 * as it needs to use a static buffer to reassemble incoming packets as
 * they arrive at the UART in unpredictable interrupt-sized chunks), so
 * we set our limit to match that in RVT.
 */

#define	MAX_PKT_TO_TARGET	255

/*
 * The above limit definition counts all bytes between the opening and
 * closing STX flags, but not DLEs inserted for binary transparency.
 */