arc: select cache settings via menuconfig

This change allows to keep board description clean and minimalistic.
This is especially helpful if one board may house different CPUs with
different features.

It is applicable to both FPGA-based boards or those that have CPUs
mounted on interchnagable daughter-boards.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index f7d2964..397b179 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -47,6 +47,25 @@
 
 endchoice
 
+config SYS_ICACHE_OFF
+	bool "Do not use Instruction Cache"
+	default n
+
+config SYS_DCACHE_OFF
+	bool "Do not use Data Cache"
+	default n
+
+config ARC_CACHE_LINE_SHIFT
+	int "Cache Line Length (as power of 2)"
+	range 5 7
+	default "6"
+	depends on !SYS_DCACHE_OFF || !SYS_DCACHE_OFF
+	help
+	  Starting with ARC700 4.9, Cache line length is configurable,
+	  This option specifies "N", with Line-len = 2 power N
+	  So line lengths of 32, 64, 128 are specified by 5,6,7, respectively
+	  Linux only supports same line lengths for I and D caches.
+
 choice
 	prompt "Target select"