sparc: Merge asm-sparc{,64}/msgbuf.h

Padding from 32 bit sparc kept using preprocessor magic

:$ diff -u include/asm-sparc/msgbuf.h include/asm-sparc64/msgbuf.h
:-- include/asm-sparc/msgbuf.h	2008-06-13 06:42:07.000000000 +0200
:++ include/asm-sparc64/msgbuf.h	2008-06-13 06:42:07.000000000 +0200
:@@ -7,17 +7,13 @@
:  * between kernel and user space.
:  *
:  * Pad space is left for:
:- * - 64-bit time_t to solve y2038 problem
:- * - 2 miscellaneous 32-bit values
:+ * - 2 miscellaneous 64-bit values
:  */
:
: struct msqid64_ds {
: 	struct ipc64_perm msg_perm;
:-	unsigned int   __pad1;
: 	__kernel_time_t msg_stime;	/* last msgsnd time */
:-	unsigned int   __pad2;
: 	__kernel_time_t msg_rtime;	/* last msgrcv time */
:-	unsigned int   __pad3;
: 	__kernel_time_t msg_ctime;	/* last change time */
: 	unsigned long  msg_cbytes;	/* current number of bytes on queue */

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>