ARC: mm: Decouple RAM base address from kernel link address

	[Needed for HSDK]

Currently the first page of system (hence RAM base) is assumed to be
@ CONFIG_LINUX_LINK_BASE, where kernel itself is linked.

However is case of HSDK platform, for reasons explained in that patch,
this is not true. kernel needs to be linked @ 0x9000_0000 while DDR
is still wired at 0x8000_0000. To properly account for this 256M of RAM,
we need to introduce a new option and base page frame accountiing off of
it.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: renamed  CONFIG_KERNEL_RAM_BASE_ADDRESS => CONFIG_LINUX_RAM_BASE
       : simplified changelog]
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index d68d36c..eee924d 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -1173,7 +1173,7 @@ noinline void __init arc_ioc_setup(void)
 	write_aux_reg(ARC_REG_IO_COH_AP0_SIZE, order_base_2(mem_sz >> 10) - 2);
 
 	/* for now assume kernel base is start of IOC aperture */
-	ioc_base = CONFIG_LINUX_LINK_BASE;
+	ioc_base = CONFIG_LINUX_RAM_BASE;
 
 	if (ioc_base % mem_sz != 0)
 		panic("IOC Aperture start must be aligned to the size of the aperture");