mtd: bcm63xxpart: Remove dependency on mach-bcm63xx

Read nvram directly from flash instead of using the in-memory copy that
mach-bcm63xx has, to remove the dependency on mach-bcm63xx and allow the
parser to work on bmips too.

Rename remaining BCM63XX defines to BCM963XX as these are properties of
the flash layout on the board.

BCM963XX_DEFAULT_PSI_SIZE changes from SZ_64K to 64 because it will be
multiplied by SZ_1K later on.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 42cc953..e83a279 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -142,7 +142,7 @@
 
 config MTD_BCM63XX_PARTS
 	tristate "BCM63XX CFE partitioning support"
-	depends on BCM63XX
+	depends on BCM63XX || BMIPS_GENERIC || COMPILE_TEST
 	select CRC32
 	help
 	  This provides partions parsing for BCM63xx devices with CFE