Finish converting CONFIG_SYS_CACHELINE_SIZE to Kconfig

We move the SYS_CACHE_SHIFT_N options from arch/arm/Kconfig to
arch/Kconfig, and introduce SYS_CACHE_SHIFT_4 to provide a size of 16.
Introduce select statements for other architectures based on current
usage.  For MIPS, we take the existing arch-specific symbol and migrate
to the generic symbol.  This lets us remove a little bit of otherwise
unused code.

Cc: Alexey Brodkin <alexey.brodkin@synopsys.com>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Atish Patra <atish.patra@wdc.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Leo <ycliang@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/arch/x86/include/asm/cache.h b/arch/x86/include/asm/cache.h
index 145b878..256a3c0 100644
--- a/arch/x86/include/asm/cache.h
+++ b/arch/x86/include/asm/cache.h
@@ -7,13 +7,8 @@
 #define __X86_CACHE_H__
 
 /*
- * If CONFIG_SYS_CACHELINE_SIZE is defined use it for DMA alignment.  Otherwise
- * use 64-bytes, a safe default for x86.
+ * Use CONFIG_SYS_CACHELINE_SIZE (which is set to 64-bytes) for DMA alignment.
  */
-#ifndef CONFIG_SYS_CACHELINE_SIZE
-#define CONFIG_SYS_CACHELINE_SIZE	64
-#endif
-
 #define ARCH_DMA_MINALIGN		CONFIG_SYS_CACHELINE_SIZE
 
 static inline void wbinvd(void)