[POWERPC] Rework Kconfig dependancies for Xilinx Virtex ppc405 platform

Reverse dependency order for Xilinx Virtex parts.  For these parts, It
makes more sense for boards/chips to specify which features they
provide instead of the features listing the parts they are implemented
in.  I think it also makes adding new board ports simpler.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

arch/ppc/platforms/4xx/Kconfig

@@ -29,6 +29,7 @@ config CPCI405
 
 config EP405
 	bool "EP405/EP405PC"
+	select EMBEDDEDBOOT
 	help
 	  This option enables support for the EP405/EP405PC boards.
 
@@ -54,11 +55,15 @@ config WALNUT
 
 config XILINX_ML300
 	bool "Xilinx-ML300"
+	select XILINX_VIRTEX_II_PRO
+	select EMBEDDEDBOOT
 	help
 	  This option enables support for the Xilinx ML300 evaluation board.
 
 config XILINX_ML403
 	bool "Xilinx-ML403"
+	select XILINX_VIRTEX_4_FX
+	select EMBEDDEDBOOT
 	help
 	  This option enables support for the Xilinx ML403 evaluation board.
 endchoice
@@ -215,18 +220,14 @@ config 405GPR
 
 config XILINX_VIRTEX_II_PRO
 	bool
-	depends on XILINX_ML300
-	default y
+	select XILINX_VIRTEX
 
 config XILINX_VIRTEX_4_FX
 	bool
-	depends on XILINX_ML403
-	default y
+	select XILINX_VIRTEX
 
 config XILINX_VIRTEX
 	bool
-	depends on XILINX_VIRTEX_II_PRO || XILINX_VIRTEX_4_FX
-	default y
 
 config STB03xxx
 	bool
@@ -235,8 +236,6 @@ config STB03xxx
 
 config EMBEDDEDBOOT
 	bool
-	depends on EP405 || XILINX_ML300 || XILINX_ML403
-	default y
 
 config IBM_OPENBIOS
 	bool