parisc: SEABIOS_HPPA_VERSION 4

New features and fixes:

* Fix firmware rendenzvous code to clear all pending external intrrupts
  before entering the waiting loop.

* STI firmware now contains additional fonts built-in, which
  can be selected with qemu command-line options:
	-fw_cfg opt/font,string=1	- a HP 8x16 font
	-fw_cfg opt/font,string=2	- a HP 6x13 font
	-fw_cfg opt/font,string=3	- a HP 10x20 font
	-fw_cfg opt/font,string=4	- a Linux 16x32 font

Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/src/parisc/parisc.c b/src/parisc/parisc.c
index 9d96986..a8dcbc4 100644
--- a/src/parisc/parisc.c
+++ b/src/parisc/parisc.c
@@ -1,6 +1,6 @@
 // Glue code for parisc architecture
 //
-// Copyright (C) 2017-2021  Helge Deller <deller@gmx.de>
+// Copyright (C) 2017-2022  Helge Deller <deller@gmx.de>
 // Copyright (C) 2019 Sven Schnelle <svens@stackframe.org>
 //
 // This file may be distributed under the terms of the GNU LGPLv3 license.
@@ -31,7 +31,7 @@
 
 #include "vgabios.h"
 
-#define SEABIOS_HPPA_VERSION 3
+#define SEABIOS_HPPA_VERSION 4
 
 /*
  * Various variables which are needed by x86 code.