sh: Calculate shm alignment at runtime.

Set the SHM alignment at runtime, based off of probed cache desc.
Optimize get_unmapped_area() to only colour align shared mappings.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/cacheflush.h b/include/asm-sh/cacheflush.h
index 92930b4..07f62ec 100644
--- a/include/asm-sh/cacheflush.h
+++ b/include/asm-sh/cacheflush.h
@@ -28,5 +28,7 @@
 		memcpy(dst, src, len);				\
 	} while (0)
 
+#define HAVE_ARCH_UNMAPPED_AREA
+
 #endif /* __KERNEL__ */
 #endif /* __ASM_SH_CACHEFLUSH_H */