ipa: rkisp1: Fix histogram weights configuration

The histogram weights are initialized to hardcoded 1's for each
histogram grid cell. The code uses the wrong variable for the grid size,
resulting in some weights having a 0 value. Fix it.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com>

src/ipa/rkisp1/algorithms/agc.cpp

@@ -175,7 +175,7 @@ void Agc::prepare(IPAContext &context, const uint32_t frame,
 	/* Set an average weighted histogram. */
 	Span<uint8_t> weights{
 		params->meas.hst_config.hist_weight,
-		context.hw->numHistogramBins
+		context.hw->numHistogramWeights
 	};
 	std::fill(weights.begin(), weights.end(), 1);
 	/* Step size can't be less than 3. */