parisc: sendfile and sendfile64 syscall cleanups

Utilize the existing compat_sys_sendfile function for 64bit kernel and add
wrappers for sendfile and sendfile64 to correctly handle the 32/64 bit sign
extension.

Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/arch/parisc/kernel/syscall_table.S b/arch/parisc/kernel/syscall_table.S
index 9180719..129fd47 100644
--- a/arch/parisc/kernel/syscall_table.S
+++ b/arch/parisc/kernel/syscall_table.S
@@ -304,7 +304,7 @@
 	ENTRY_SAME(gettid)
 	ENTRY_OURS(readahead)
 	ENTRY_SAME(tkill)
-	ENTRY_SAME(sendfile64)
+	ENTRY_DIFF(sendfile64)
 	ENTRY_COMP(futex)		/* 210 */
 	ENTRY_COMP(sched_setaffinity)
 	ENTRY_COMP(sched_getaffinity)