Make `readPin` output a 0 or 1 when using AVR to match ChibiOS's version of `readPin`

quantum/quantum.h

@@ -161,7 +161,7 @@ extern uint32_t default_layer_state;
         }
     }
 
-    #define readPin(pin) (PIN_ADDRESS(pin, 0) & _BV(pin & 0xF))
+    #define readPin(pin) ((bool)(PIN_ADDRESS(pin, 0) & _BV(pin & 0xF)))
 #elif defined(PROTOCOL_CHIBIOS)
     #define pin_t ioline_t
     #define setPinInput(pin) palSetLineMode(pin, PAL_MODE_INPUT)