powerpc/mm: Simplify page size kconfig dependencies

For config options with only a single value, guarding the single value
with 'if' is the same as adding a 'depends' statement. And it's more
standard to just use 'depends'.

And if the option has both an 'if' guard and a 'depends' we can collapse
them into a single 'depends' by combining them with &&.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

arch/powerpc/Kconfig

@@ -565,16 +565,17 @@ config PPC_4K_PAGES
 	bool "4k page size"
 
 config PPC_16K_PAGES
-	bool "16k page size" if 44x || PPC_8xx
+	bool "16k page size"
+	depends on 44x || PPC_8xx
 
 config PPC_64K_PAGES
-	bool "64k page size" if 44x || PPC_STD_MMU_64 || PPC_BOOK3E_64
-	depends on !PPC_FSL_BOOK3E
+	bool "64k page size"
+	depends on !PPC_FSL_BOOK3E && (44x || PPC_STD_MMU_64 || PPC_BOOK3E_64)
 	select PPC_HAS_HASH_64K if PPC_STD_MMU_64
 
 config PPC_256K_PAGES
-	bool "256k page size" if 44x
-	depends on !STDBINUTILS
+	bool "256k page size"
+	depends on 44x && !STDBINUTILS
 	help
 	  Make the page size 256k.