Fix up GH2 correction

src/calng/corrections/Gotthard2Correction.py

@@ -33,6 +33,9 @@ class CorrectionFlags(enum.IntFlag):
 
 
 class Gotthard2CpuRunner(base_kernel_runner.BaseKernelRunner):
+    _gpu_based = False
+    _xp = np
+
     def __init__(
         self,
         pixels_x,
@@ -69,7 +72,7 @@ class Gotthard2CpuRunner(base_kernel_runner.BaseKernelRunner):
         self.processed_data = None  # will just point to buffer we're given
 
     @property
-    def input_data_views(self):
+    def preview_data_views(self):
         return (self.input_data, self.processed_data)
 
     def load_data(self, image_data, input_gain_stage):