[ARM] use asm/sections.h

Update to use the asm/sections.h header rather than declaring these
symbols ourselves.  Change __data_start to _data to conform with the
naming found within asm/sections.h.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index c0b9a78..2ab5f96 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -17,6 +17,7 @@
 
 #include <asm/cputype.h>
 #include <asm/mach-types.h>
+#include <asm/sections.h>
 #include <asm/setup.h>
 #include <asm/sizes.h>
 #include <asm/tlb.h>
@@ -730,7 +731,7 @@
 
 #ifdef CONFIG_XIP_KERNEL
 	/* The XIP kernel is mapped in the module area -- skip over it */
-	addr = ((unsigned long)&_etext + PGDIR_SIZE - 1) & PGDIR_MASK;
+	addr = ((unsigned long)_etext + PGDIR_SIZE - 1) & PGDIR_MASK;
 #endif
 	for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE)
 		pmd_clear(pmd_off_k(addr));
@@ -756,10 +757,10 @@
 	 * Note that this can only be in node 0.
 	 */
 #ifdef CONFIG_XIP_KERNEL
-	reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start,
+	reserve_bootmem_node(pgdat, __pa(_data), _end - _data,
 			BOOTMEM_DEFAULT);
 #else
-	reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext,
+	reserve_bootmem_node(pgdat, __pa(_stext), _end - _stext,
 			BOOTMEM_DEFAULT);
 #endif
 
@@ -838,7 +839,7 @@
 #ifdef CONFIG_XIP_KERNEL
 	map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
 	map.virtual = MODULES_VADDR;
-	map.length = ((unsigned long)&_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;
+	map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;
 	map.type = MT_ROM;
 	create_mapping(&map);
 #endif