serial: tegra-utc: Add driver for Tegra UART Trace Controller (UTC)

The Tegra264 SoC supports the UART Trace Controller (UTC), which allows
multiple firmware clients (up to 16) to share a single physical UART.
Each client is provided with its own interrupt and has access to a
128-character wide FIFO for both transmit (TX) and receive (RX)
operations.

Add tegra-utc driver to support Tegra UART Trace Controller (UTC)
client.

Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20250213125612.4705-3-kkartik@nvidia.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>