parisc: #include <linux/compiler.h> for unlikely() in <asm/ptrace.h>

Currently <linux/compiler.h> isn't included at all (not even
transitively) in <asm/ptrace.h>.
arch/parisc/kernel/asm-offsets.c just happens to include the following
chain of includes before <asm/ptrace.h>:

	<linux/sched.h>
	-> <asm/processor.h>
	-> <asm/hardware.h>
	-> <linux/mod_devicetable.h>
	-> <linux/uuid.h>
	-> <linux/string.h>
	-> <linux/compiler.h>

. That chain will be broken, because in one of the next commits
<asm/hardware.h> is changed to only include <linux/device-id/parisc.h>
instead of <linux/mod_devicetable.h>. So to ensure
arch/parisc/kernel/asm-offsets.c knows about unlikely() even after that
change, #include <linux/compiler.h> explicitly.

Link: https://patch.msgid.link/0574a2b73363c3cbf21c55c27455c3cecfb33583.1782808461.git.u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>

arch/parisc/include/asm/ptrace.h

@@ -7,6 +7,7 @@
 
 #include <asm/assembly.h>
 #include <uapi/asm/ptrace.h>
+#include <linux/compiler.h>
 
 #define task_regs(task) ((struct pt_regs *) ((char *)(task) + TASK_REGS))