locks: linker variables to calculate per-cpu bakery lock size

This patch introduces explicit linker variables to mark the start and
end of the per-cpu bakery lock section to help bakery_lock_normal.c
calculate the size of the section. This patch removes the previously
used '__PERCPU_BAKERY_LOCK_SIZE__' linker variable to make the code
uniform across GNU linker and ARM linker.

Change-Id: Ie0c51702cbc0fe8a2076005344a1fcebb48e7cca
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/mediatek/mt6795/bl31.ld.S b/plat/mediatek/mt6795/bl31.ld.S
index 6ec7a1a..cf68b71 100644
--- a/plat/mediatek/mt6795/bl31.ld.S
+++ b/plat/mediatek/mt6795/bl31.ld.S
@@ -113,9 +113,11 @@
          */
         . = ALIGN(CACHE_WRITEBACK_GRANULE);
         __BAKERY_LOCK_START__ = .;
+        __PERCPU_BAKERY_LOCK_START__ = .;
         *(bakery_lock)
         . = ALIGN(CACHE_WRITEBACK_GRANULE);
-        __PERCPU_BAKERY_LOCK_SIZE__ = ABSOLUTE(. - __BAKERY_LOCK_START__);
+        __PERCPU_BAKERY_LOCK_END__ = .;
+        __PERCPU_BAKERY_LOCK_SIZE__ = ABSOLUTE(__PERCPU_BAKERY_LOCK_END__ - __PERCPU_BAKERY_LOCK_START__);
         . = . + (__PERCPU_BAKERY_LOCK_SIZE__ * (PLATFORM_CORE_COUNT - 1));
         __BAKERY_LOCK_END__ = .;
 #ifdef PLAT_PERCPU_BAKERY_LOCK_SIZE