Fix Spindle/Laser compile error

[Ludy87]

Fixes #14307

[Ludy87]

@thinkyhead

uint8 goes from 0 to 255

SPEED_POWER_MIN is 5000
SPEED_POWER_MAX is 30000

is coming to overflow, so I had put on uint16

---

MENU_ITEM_EDIT_CALLBACK(uint8, MSG_LASER_POWER, &spindle_laser_power, SPEED_POWER_MIN, SPEED_POWER_MAX, update_spindle_laser_power);

MENU_ITEM_EDIT_CALLBACK(uint8, "Laser power", uint8_t=0, 5000, 30000, void update_spindle_laser_power());

[thinkyhead]

There will be more code needing changes to support these variable SPEED_POWER_MAX values. I'm rewriting the Spindle / Laser code as a class, and there the size of the power will be set using TypeSelector<(SPEED_POWER_MAX)>255, uint16_t, uint8_t>.