Relocate PS2 code (#14895)

* Relocate ps2 protocol code

* clang

* Move makefile logic

platforms/avr/drivers/ps2/ps2_io.c

@@ -0,0 +1,51 @@
+#include <stdbool.h>
+#include "ps2_io.h"
+#include "gpio.h"
+#include "wait.h"
+
+/* Check port settings for clock and data line */
+#if !(defined(PS2_CLOCK_PIN))
+#    error "PS/2 clock setting is required in config.h"
+#endif
+
+#if !(defined(PS2_DATA_PIN))
+#    error "PS/2 data setting is required in config.h"
+#endif
+
+/*
+ * Clock
+ */
+void clock_init(void) {}
+
+void clock_lo(void) {
+    // Transition from input with pull-up to output low via Hi-Z instead of output high
+    writePinLow(PS2_CLOCK_PIN);
+    setPinOutput(PS2_CLOCK_PIN);
+}
+
+void clock_hi(void) { setPinInputHigh(PS2_CLOCK_PIN); }
+
+bool clock_in(void) {
+    setPinInputHigh(PS2_CLOCK_PIN);
+    wait_us(1);
+    return readPin(PS2_CLOCK_PIN);
+}
+
+/*
+ * Data
+ */
+void data_init(void) {}
+
+void data_lo(void) {
+    // Transition from input with pull-up to output low via Hi-Z instead of output high
+    writePinLow(PS2_DATA_PIN);
+    setPinOutput(PS2_DATA_PIN);
+}
+
+void data_hi(void) { setPinInputHigh(PS2_DATA_PIN); }
+
+bool data_in(void) {
+    setPinInputHigh(PS2_DATA_PIN);
+    wait_us(1);
+    return readPin(PS2_DATA_PIN);
+}