boards/adafruit_feather_rp2350.h: add PICO_XOSC_STARTUP_DELAY_MULTIPLIER 64 (#2248)

Author: dhalbert

src/boards/include/boards/adafruit_feather_rp2350.h

@@ -16,6 +16,11 @@
 #ifndef _BOARDS_ADAFRUIT_FEATHER_RP2350_H
 #define _BOARDS_ADAFRUIT_FEATHER_RP2350_H
 
+// On some samples, the xosc can take longer to stabilize than is usual
+#ifndef PICO_XOSC_STARTUP_DELAY_MULTIPLIER
+#define PICO_XOSC_STARTUP_DELAY_MULTIPLIER 64
+#endif
+
 // For board detection
 #define ADAFRUIT_FEATHER_RP2350