ipa: rpi: Fix printing of utils::Duration

`utils::Duration` derives from `std::chrono::duration<...>`, but multiplying
it yields an `std::chrono::duration<...>`, not `Duration`. chrono duration
types only have `operator<<` in C++20 or later, so this usage should not
compile. It only did so because the `operator<<` for `Duration` was in
the `libcamera` namespace and `Duration` has an implicit constructor from
any chrono duration type.

This will cease to work when that operator is moved into the `utils` namespace
for ADL purposes. So fix it by making the cast to `Duration` explicit.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Naushir Patuck <naush@raspberrypi.com>

src/ipa/rpi/common/ipa_base.cpp

@@ -604,7 +604,7 @@ void IpaBase::setMode(const IPACameraSensorInfo &sensorInfo)
 			mode_.minLineLength = adjustedLineLength;
 		} else {
 			LOG(IPARPI, Error)
-				<< "Sensor minimum line length of " << pixelTime * mode_.width
+				<< "Sensor minimum line length of " << Duration(pixelTime * mode_.width)
 				<< " (" << 1us / pixelTime << " MPix/s)"
 				<< " is below the minimum allowable ISP limit of "
 				<< adjustedLineLength