RPI_PICO_PPP: Tweak flash/fw alloc to fit PPP support.

micropython/board/RPI_PICO_PPP/mpconfigboard.h

@@ -1,6 +1,6 @@
 // Board and hardware specific configuration
 #define MICROPY_HW_BOARD_NAME                   "Raspberry Pi Pico"
-#define MICROPY_HW_FLASH_STORAGE_BYTES          (1408 * 1024)
+#define MICROPY_HW_FLASH_STORAGE_BYTES          (1024 * 1024)
 
 // Enable networking.
 #define MICROPY_PY_NETWORK                      1