android: make persistent_ram based drivers depend on HAVE_MEMBLOCK

m68k doesn't have memblock_reserve, which causes a build failure
with allmodconfig.  Make PERSISTENT_RAM and RAM_CONSOLE depend on
HAVE_MEMBLOCK.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/Kconfig

@@ -27,13 +27,14 @@ config ANDROID_LOGGER
 
 config ANDROID_PERSISTENT_RAM
 	bool
+	depends on HAVE_MEMBLOCK
 	select REED_SOLOMON
 	select REED_SOLOMON_ENC8
 	select REED_SOLOMON_DEC8
 
 config ANDROID_RAM_CONSOLE
 	bool "Android RAM buffer console"
-	depends on !S390 && !UML
+	depends on !S390 && !UML && HAVE_MEMBLOCK
 	select ANDROID_PERSISTENT_RAM
 	default n