Update 072 based CannonKeys boards to rely on core QMK support (#8716)

* Swap CannonKeys 072 boards over to rely on core QMK backlight support

* Rename keymap

* Rename via_tsangan back to via

keyboards/cannonkeys/chimera65/config.h

@@ -33,6 +33,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_ROW_PINS { A13, A14, A15, C13, B8 }
 #define DIODE_DIRECTION COL2ROW
 
+#define BACKLIGHT_PIN           A6
+#define BACKLIGHT_PWM_DRIVER    PWMD3
+#define BACKLIGHT_PWM_CHANNEL   1
+#define BACKLIGHT_PAL_MODE      1
 #define BACKLIGHT_LEVELS 6
 #define BACKLIGHT_BREATHING
 #define BREATHING_PERIOD 6