mtd: bcm47xxpart: alloc memory for more partitions

This is needed for some new Netgear devices (e.g. R6250).
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/bcm47xxpart.c

@@ -15,8 +15,12 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
 
-/* 10 parts were found on sflash on Netgear WNDR4500 */
-#define BCM47XXPART_MAX_PARTS		12
+/*
+ * NAND flash on Netgear R6250 was verified to contain 15 partitions.
+ * This will result in allocating too big array for some old devices, but the
+ * memory will be freed soon anyway (see mtd_device_parse_register).
+ */
+#define BCM47XXPART_MAX_PARTS		20
 
 /*
  * Amount of bytes we read when analyzing each block of flash memory.