libc: ARM: update syscalls with new script

Used the new gensyscalls.py script to update the ARM syscalls with the
BEGIN(x) and END(x) macros to give size information for the code of the
syscall. Useful for valgrind.

Change-Id: I8c481c8928401ac110fd19b087f7d67e4db39326

libc/arch-arm/syscalls/getpid.S

@@ -1,13 +1,8 @@
 /* autogenerated by gensyscalls.py */
+#include <machine/asm.h>
 #include <sys/linux-syscalls.h>
 
-    .text
-    .type getpid, #function
-    .globl getpid
-    .align 4
-    .fnstart
-
-getpid:
+ENTRY(getpid)
     .save   {r4, r7}
     stmfd   sp!, {r4, r7}
     ldr     r7, =__NR_getpid
@@ -16,4 +11,4 @@ getpid:
     movs    r0, r0
     bxpl    lr
     b       __set_syscall_errno
-    .fnend
+END(getpid)