[Keyboard] CannonKeys Instant60 Keyboard (#5433)

* Instant 60

* Instant60 changes again

* turn off LSE and features

* Working RGB underglow 🎉

* Add missing files

* Update keymap to have reset

* Backlighting on

* Backlight code for instant60

* Move 072 files to common folder and use it in Instant60

* Updates

* Update keyboards/cannonkeys/instant60/rules.mk

Co-Authored-By: awkannan <andrew.kannan@klaviyo.com>

keyboards/cannonkeys/stm32f072/led_custom.h

@@ -0,0 +1,6 @@
+#pragma once
+
+void backlight_task(void);
+void breathing_interrupt_disable(void);
+void breathing_interrupt_enable(void);
+void breathing_toggle(void);