firmware: bcm47xx_nvram: Support small (0x6000 B) NVRAM partitions

Some old devices with 4 MiB flashes were using 0x1000 block size and
could use smaller (0x6000 bytes) flash partition for storing NVRAM
content. This adds support for reading NVRAM on Netgear WNR1000 V3.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/19005/Signed-off-by: James Hogan <jhogan@kernel.org>

drivers/firmware/broadcom/bcm47xx_nvram.c

@@ -36,7 +36,7 @@ struct nvram_header {
 
 static char nvram_buf[NVRAM_SPACE];
 static size_t nvram_len;
-static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
+static const u32 nvram_sizes[] = {0x6000, 0x8000, 0xF000, 0x10000};
 
 static u32 find_nvram_size(void __iomem *end)
 {