tmc: Simplify internal DUMP_TMC interface

Only the tmc2208 driver needs special read register translation logic.
Rework the code so a default implementation is available for all the
other drivers.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/extras/tmc2660.py

@@ -236,7 +236,7 @@ class TMC2660:
         self.mcu_tmc = MCU_TMC2660_SPI(config, Registers, self.fields)
         # Register commands
         cmdhelper = tmc.TMCCommandHelper(config, self.mcu_tmc)
-        cmdhelper.setup_register_dump(self.query_registers)
+        cmdhelper.setup_register_dump(ReadRegisters)
 
         # DRVCTRL
         mh = tmc.TMCMicrostepHelper(config, self.mcu_tmc)
@@ -274,9 +274,5 @@ class TMC2660:
         set_config_field(config, "DISS2G", 0)
         set_config_field(config, "TS2G", 3)
 
-    def query_registers(self, print_time=0.):
-        return [(reg_name, self.mcu_tmc.get_register(reg_name))
-                for reg_name in ReadRegisters]
-
 def load_config_prefix(config):
     return TMC2660(config)