microblaze: Add consistent code

Remove ancient Kconfig option for consistent code.
MMU uses cache inhibit pages.

noMMU uses UNCACHE SHADOW feature where is used double ram size.
For example:
Physical ram is 256MB and cache are setup to cover the same size.
But if you setup in HW that size is 512MB and cache covers 256MB
than you can use adresses from 256-512MB without caches and
correspond with 0-256MB with cache. That's why I am using
dcache base/high addresses to find out uncache area.

Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index e451c08..203ec61 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -156,6 +156,15 @@
 comment "Default settings for advanced configuration options are used"
 	depends on !ADVANCED_OPTIONS
 
+config XILINX_UNCACHED_SHADOW
+	bool "Are you using uncached shadow for RAM ?"
+	depends on ADVANCED_OPTIONS && !MMU
+	default n
+	help
+	  This is needed to be able to allocate uncachable memory regions.
+	  The feature requires the design to define the RAM memory controller
+	  window to be twice as large as the actual physical memory.
+
 config HIGHMEM_START_BOOL
 	bool "Set high memory pool address"
 	depends on ADVANCED_OPTIONS && HIGHMEM