mcu: Do not invert the direction of pullup pins by default

A pullup setting on an input pin (ie, '^') should enable the hardware
pullup resistor, but it should not invert the trigger level (ie, it
should remain trigger on high).  Those that need to change the trigger
level (ie, trigger on low) must now do that explicitly (ie, '^!').
This makes the code match what other firmwares do.

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

config/avrsim.cfg

@@ -11,7 +11,7 @@ enable_pin: ar25
 step_distance: .0225
 max_velocity: 500
 max_accel: 3000
-endstop_pin: ^!ar0
+endstop_pin: ^ar0
 position_min: -0.25
 position_endstop: 0
 position_max: 200
@@ -24,7 +24,7 @@ enable_pin: ar25
 step_distance: .0225
 max_velocity: 500
 max_accel: 3000
-endstop_pin: ^!ar1
+endstop_pin: ^ar1
 position_min: -0.25
 position_endstop: 0
 position_max: 200
@@ -37,7 +37,7 @@ enable_pin: ar25
 step_distance: .005
 max_velocity: 250
 max_accel: 30
-endstop_pin: ^!ar2
+endstop_pin: ^ar2
 position_min: 0.1
 position_endstop: 0.5
 position_max: 200

config/makergear-m2-2012.cfg

@@ -10,7 +10,7 @@ enable_pin: !PA7
 step_distance: .0225
 max_velocity: 500
 max_accel: 3000
-endstop_pin: ^PB6
+endstop_pin: ^!PB6
 homing_speed: 50.0
 homing_stepper_phases: 32
 homing_endstop_accuracy: .200
@@ -25,7 +25,7 @@ enable_pin: !PA6
 step_distance: .0225
 max_velocity: 500
 max_accel: 3000
-endstop_pin: ^PB5
+endstop_pin: ^!PB5
 homing_speed: 50.0
 homing_stepper_phases: 32
 homing_endstop_accuracy: .200
@@ -40,7 +40,7 @@ enable_pin: !PA5
 step_distance: .005
 max_velocity: 250
 max_accel: 30
-endstop_pin: ^PB4
+endstop_pin: ^!PB4
 homing_speed: 4.0
 homing_retract_dist: 2.0
 homing_stepper_phases: 32