Remove read_fpga_mask_R function because there's no ro mask

SDP/SDP/SDP.py

@@ -247,13 +247,6 @@ class SDP(Device):
     # ------------------
     # Attributes methods
     # ------------------
-    @only_when_on
-    @fault_on_error
-    def read_fpga_mask_R(self):
-        """Return the fpga_mask_R attribute."""
-        self._fpga_mask_R = numpy.array(self.attribute_mapping["fpga_mask_R"].get_value())
-        return self._fpga_mask_R
-
     @only_when_on
     @fault_on_error
     def read_fpga_mask_RW(self):