microblaze: Define percpu sestion in linker file

Adding SMP requires to have percpu section defined.
Signed-off-by: Stefan Asserhall <stefan.asserhall@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

arch/microblaze/kernel/vmlinux.lds.S

@@ -13,6 +13,7 @@ ENTRY(microblaze_start)
 
 #define RO_EXCEPTION_TABLE_ALIGN	16
 
+#include <asm/cache.h>
 #include <asm/page.h>
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/thread_info.h>
@@ -89,6 +90,8 @@ SECTIONS {
 		_KERNEL_SDA_BASE_ = _ssro + (_ssro_size / 2) ;
 	}
 
+	PERCPU_SECTION(L1_CACHE_BYTES)
+
 	. = ALIGN(PAGE_SIZE);
 	__init_begin = .;