MIPS: simplify relocated _G_O_T_ address calculation

The difference between the address of the original
and the relocated _GLOBAL_OFFSET_TABLE_ is always
the same as the relocation offset.

The relocation offset is already computed and it is
available in the 's1/t6' register. Use that to adjust
the relocated _G_O_T_ address, instead of calculating
the offset again from the _gp value.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>
Cc: Xiangfu Liu <xiangfu@openmobilefree.net>
diff --git a/arch/mips/cpu/mips64/start.S b/arch/mips/cpu/mips64/start.S
index 80e6bb1..1522594 100644
--- a/arch/mips/cpu/mips64/start.S
+++ b/arch/mips/cpu/mips64/start.S
@@ -193,7 +193,6 @@
 	jr	t0
 	 nop
 
-	.dword	_gp
 	.dword	_GLOBAL_OFFSET_TABLE_
 	.dword	uboot_end_data
 	.dword	uboot_end
@@ -208,9 +207,7 @@
 	 */
 	ld	t3, -8(t0)		# t3 <-- num_got_entries
 	ld	t8, -32(t0)		# t8 <-- _GLOBAL_OFFSET_TABLE_
-	ld	t9, -40(t0)		# t9 <-- _gp
-	dsub	t8, t9			# compute offset
-	dadd	t8, t8, gp		# t8 now holds relocated _G_O_T_
+	dadd	t8, s1			# t8 now holds relocated _G_O_T_
 	daddi	t8, t8, 16		# skipping first two entries
 	dli	t2, 2
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