Added first draft of multithresholding python function

src/finn/core/multi_thresholding.py

+import numpy as np
+
+
+def compare(value, threshold):
+        if (value >= threshold):
+                res = 1.0
+        else:
+                res = 0.0
+        return res
+
+def execute(inputs,thresholds):
+
+        inputs_reshaped = inputs.reshape((thresholds.shape[1], -1))
+        num_channels = thresholds.shape[0]
+        ret = np.zeros_like(inputs_reshaped)
+        channel_interval = int(inputs_reshaped.shape[1]/num_channels)
+
+        i=-1
+        for t in thresholds:
+                i+=1
+                if i == 0:
+                        ce1_low_lim=0
+                else:
+                        ce1_low_lim=i*channel_interval
+                ce1_up_lim=(i+1)*channel_interval
+
+                for c in range(thresholds.shape[1]):
+                        for ce0 in range(inputs_reshaped.shape[0]):
+                                for ce1 in range(ce1_low_lim,ce1_up_lim):
+                                        ret[ce0][ce1] += compare(inputs_reshaped[ce0][ce1], t[c])
+
+
+        return ret.reshape(inputs.shape)
+