Fix issues with .note.GNU-stack section directives.

bionic/libm/x86_64/s_log1p.S:809:2: error: changed section type for .note.GNU-stack, expected: 0x1
 .section .note.GNU-stack, ""
 ^

These assembly sources are missing @progbits to set the section flags
correctly. Without it, they end up denoting a different section type. By
adding the @progbits explicitly, we see the same section flags with
readelf.

[ 4] .note.GNU-stack   PROGBITS        0000000000000000 000593 000000 00      0   0  1

Bug: http://b/155835175
Test: m for aosp_x86_64
Change-Id: Ifff35d35f5f9ded5938e88677b18805809820e9f
diff --git a/libm/x86_64/e_atan2.S b/libm/x86_64/e_atan2.S
index f9baea9..f0ba43c 100644
--- a/libm/x86_64/e_atan2.S
+++ b/libm/x86_64/e_atan2.S
@@ -1219,7 +1219,7 @@
 	.type	EXPMASK,@object
 	.size	EXPMASK,8
 	.data
-	.section .note.GNU-stack, ""
+	.section .note.GNU-stack, "",@progbits
 // -- Begin DWARF2 SEGMENT .eh_frame
 	.section .eh_frame,"a",@progbits
 .eh_frame_seg: