sh: pselect6 and ppoll, along with signal trampoline rework.

This implements support for ppoll() and pselect6()..

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/syscalls.S

@@ -319,34 +319,35 @@ ENTRY(sys_call_table)
 	.long sys_mq_getsetattr
 	.long sys_kexec_load
 	.long sys_waitid
-	.long sys_add_key		/* 285 */
+	.long sys_ni_syscall		/* 285 */
+	.long sys_add_key
 	.long sys_request_key
 	.long sys_keyctl
 	.long sys_ioprio_set
-	.long sys_ioprio_get
-	.long sys_inotify_init		/* 290 */
+	.long sys_ioprio_get		/* 290 */
+	.long sys_inotify_init
 	.long sys_inotify_add_watch
 	.long sys_inotify_rm_watch
 	.long sys_migrate_pages
-	.long sys_openat
-	.long sys_mkdirat		/* 295 */
+	.long sys_openat		/* 295 */
+	.long sys_mkdirat
 	.long sys_mknodat
 	.long sys_fchownat
 	.long sys_futimesat
-	.long sys_fstatat64
-	.long sys_unlinkat		/* 300 */
+	.long sys_fstatat64		/* 300 */
+	.long sys_unlinkat
 	.long sys_renameat
 	.long sys_linkat
 	.long sys_symlinkat
-	.long sys_readlinkat
-	.long sys_fchmodat		/* 305 */
+	.long sys_readlinkat		/* 305 */
+	.long sys_fchmodat
 	.long sys_faccessat
-	.long sys_ni_syscall		/* Reserved for pselect6 */
-	.long sys_ni_syscall		/* Reserved for ppoll */
-	.long sys_unshare
-	.long sys_set_robust_list	/* 310 */
+	.long sys_pselect6
+	.long sys_ppoll
+	.long sys_unshare		/* 310 */
+	.long sys_set_robust_list
 	.long sys_get_robust_list
 	.long sys_splice
 	.long sys_sync_file_range
-	.long sys_tee
-	.long sys_vmsplice		/* 315 */
+	.long sys_tee			/* 315 */
+	.long sys_vmsplice