Relocate pca9555 driver to core (#6563)

* Move pca9555 files to central location

* Get pca9555 boards compiling

* Slight alignment of rules.mk

keyboards/moon/rules.mk

@@ -1,6 +1,3 @@
-# Project specific files
-SRC += i2c_master.c pca9555.c matrix.c
-
 # MCU name
 MCU = atmega32u4
 
@@ -50,10 +47,6 @@ OPT_DEFS += -DINTERRUPT_CONTROL_ENDPOINT
 #   atmega32a    bootloadHID
 BOOTLOADER = atmel-dfu
 
-
-# Supported layouts
-LAYOUTS = tkl_ansi tkl_iso
-
 # Build Options
 #   change yes to no to disable
 #
@@ -74,4 +67,13 @@ BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
 AUDIO_ENABLE = no           # Audio output on port C6
 FAUXCLICKY_ENABLE = no      # Use buzzer to emulate clicky switches
 HD44780_ENABLE = no         # Enable support for HD44780 based LCDs (+400)
+
+# custom matrix setup
 CUSTOM_MATRIX = yes
+
+VPATH += drivers/gpio
+SRC += pca9555.c matrix.c
+QUANTUM_LIB_SRC += i2c_master.c
+
+# Supported layouts
+LAYOUTS = tkl_ansi tkl_iso