spi: drop "select SPI_MASTER_OF"

There is no Kconfig symbol named SPI_MASTER_OF. The select statement for
that symbol is a nop. Drop it.

While we're touching that Kconfig entry also drop a superfluous
dependency on SPI (this entry is wrapped in "if SPI" / "endif").
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

drivers/spi/Kconfig

@@ -174,8 +174,7 @@ config SPI_LM70_LLP
 
 config SPI_MPC52xx
 	tristate "Freescale MPC52xx SPI (non-PSC) controller support"
-	depends on PPC_MPC52xx && SPI
-	select SPI_MASTER_OF
+	depends on PPC_MPC52xx
 	help
 	  This drivers supports the MPC52xx SPI controller in master SPI
 	  mode.