Support 32-bit ARM vdso.

Linux 4.1 added this.

Bug: http://b/19198045
Change-Id: I28be802ff403a61dd6733a001411b3ff05fef5a5
diff --git a/libc/arch-arm/syscalls/clock_gettime.S b/libc/arch-arm/syscalls/__clock_gettime.S
similarity index 87%
rename from libc/arch-arm/syscalls/clock_gettime.S
rename to libc/arch-arm/syscalls/__clock_gettime.S
index 61a95dd..30eff03 100644
--- a/libc/arch-arm/syscalls/clock_gettime.S
+++ b/libc/arch-arm/syscalls/__clock_gettime.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(clock_gettime)
+ENTRY(__clock_gettime)
     mov     ip, r7
     .cfi_register r7, ip
     ldr     r7, =__NR_clock_gettime
@@ -13,4 +13,4 @@
     bxls    lr
     neg     r0, r0
     b       __set_errno_internal
-END(clock_gettime)
+END(__clock_gettime)
diff --git a/libc/arch-arm/syscalls/gettimeofday.S b/libc/arch-arm/syscalls/__gettimeofday.S
similarity index 88%
rename from libc/arch-arm/syscalls/gettimeofday.S
rename to libc/arch-arm/syscalls/__gettimeofday.S
index f5ed674..de0eca5 100644
--- a/libc/arch-arm/syscalls/gettimeofday.S
+++ b/libc/arch-arm/syscalls/__gettimeofday.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(gettimeofday)
+ENTRY(__gettimeofday)
     mov     ip, r7
     .cfi_register r7, ip
     ldr     r7, =__NR_gettimeofday
@@ -13,4 +13,4 @@
     bxls    lr
     neg     r0, r0
     b       __set_errno_internal
-END(gettimeofday)
+END(__gettimeofday)