of: make drivers depend on CONFIG_OF instead of CONFIG_PPC_OF

Some OF drivers could likely be used on non-powerpc OF based platforms,
so fix the kconfig depends to be CONFIG_OF instead of CONFIG_PPC_OF.

Compile tested on ARM and sparc.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/mtd/Kconfig b/drivers/mtd/Kconfig
index 1e2cbf5..b1f7689 100644
--- a/drivers/mtd/Kconfig
+++ b/drivers/mtd/Kconfig
@@ -159,7 +159,7 @@
 
 config MTD_OF_PARTS
 	tristate "Flash partition map based on OF description"
-	depends on (MICROBLAZE || PPC_OF) && MTD_PARTITIONS
+	depends on OF && MTD_PARTITIONS
 	help
 	  This provides a partition parsing function which derives
 	  the partition map from the children of the flash node,