parisc: Prevent booting 64-bit kernels on PA1.x machines

Bail out early with error message when trying to boot a 64-bit kernel on
32-bit machines. This fixes the previous commit to include the check for
true 64-bit kernels as well.
Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: 591d2108 ("parisc: Add runtime check to prevent PA2.0 kernels on PA1.x machines")
Cc:  <stable@vger.kernel.org> # v6.0+

arch/parisc/kernel/head.S

@@ -70,9 +70,8 @@ $bss_loop:
 	stw,ma          %arg2,4(%r1)
 	stw,ma          %arg3,4(%r1)
 
-#if !defined(CONFIG_64BIT) && defined(CONFIG_PA20)
-	/* This 32-bit kernel was compiled for PA2.0 CPUs. Check current CPU
-	 * and halt kernel if we detect a PA1.x CPU. */
+#if defined(CONFIG_PA20)
+	/* check for 64-bit capable CPU as required by current kernel */
 	ldi		32,%r10
 	mtctl		%r10,%cr11
 	.level 2.0