riscv64: fix comments borrowed from or1k port

Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>

libpthread/nptl/sysdeps/riscv64/libc-tls.c

@@ -17,7 +17,7 @@
 #include <sysdeps/generic/libc-tls.c>
 #include <dl-tls.h>
 
-/* On OpenRISC, linker optimizations are not required, so __tls_get_addr
+/* On RISC-V 64, linker optimizations are not required, so __tls_get_addr
    can be called even in statically linked binaries.  In this case module
    must be always 1 and PT_TLS segment exist in the binary, otherwise it
    would not link.  */

libpthread/nptl/sysdeps/riscv64/tls.h

@@ -1,4 +1,4 @@
-/* Definition for thread-local data handling.  NPTL/OR1K version.
+/* Definition for thread-local data handling.  NPTL/RISCV64 version.
    Copyright (C) 2005, 2007, 2011 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -70,7 +70,7 @@ register tcbhead_t *__thread_self __asm__("tp");
  *  ------------------------------------
  *  | PRE | TCB | TLS MEMORY ..        |
  *  ------------------------------------
- *              ^ r10 / TP
+ *              ^ x4 / TP
  *
  * PRE is the struct pthread described below
  * TCB is tcbhead_t