toolhead: Specify maximum acceleration and velocity in toolhead class

Change the config file so the maximum accel and velocity are specified
in the "printer" section instead of the individual "stepper" sections.
The underlying code limits the velocity and accel of the toolhead
relative to the print object, so it makes sense to configure the
system that was as well.

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

config/makergear-m2-2012.cfg

@@ -8,8 +8,6 @@ step_pin: PC0
 dir_pin: !PL1
 enable_pin: !PA7
 step_distance: .0225
-max_velocity: 500
-max_accel: 3000
 endstop_pin: ^!PB6
 homing_speed: 50.0
 homing_stepper_phases: 32
@@ -23,8 +21,6 @@ step_pin: PC1
 dir_pin: PL0
 enable_pin: !PA6
 step_distance: .0225
-max_velocity: 500
-max_accel: 3000
 endstop_pin: ^!PB5
 homing_speed: 50.0
 homing_stepper_phases: 32
@@ -38,8 +34,6 @@ step_pin: PC2
 dir_pin: !PL2
 enable_pin: !PA5
 step_distance: .005
-max_velocity: 250
-max_accel: 30
 endstop_pin: ^!PB4
 homing_speed: 4.0
 homing_retract_dist: 2.0
@@ -105,4 +99,8 @@ custom:
 
 [printer]
 kinematics: cartesian
+max_velocity: 500
+max_accel: 3000
+max_z_velocity: 250
+max_z_accel: 30
 motor_off_time: 600