[IA64] rename _bss to __bss_start

Rename _bss to __bss_start as on other architectures.  That makes it
possible to use the <linux/sections.h> instead of own declarations.  Also
add __bss_stop because that symbol exists on other architectures.

Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index 2b3751e..4ac2b1f 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -95,7 +95,6 @@
 	.name	= "Kernel bss",
 	.flags	= IORESOURCE_BUSY | IORESOURCE_MEM
 };
-extern char _text[], _end[], _etext[], _edata[], _bss[];
 
 unsigned long ia64_max_cacheline_size;
 
@@ -206,7 +205,7 @@
 	code_resource.end   = ia64_tpa(_etext) - 1;
 	data_resource.start = ia64_tpa(_etext);
 	data_resource.end   = ia64_tpa(_edata) - 1;
-	bss_resource.start  = ia64_tpa(_bss);
+	bss_resource.start  = ia64_tpa(__bss_start);
 	bss_resource.end    = ia64_tpa(_end) - 1;
 	efi_initialize_iomem_resources(&code_resource, &data_resource,
 			&bss_resource);