[PARISC] Build fixes for power.c

<linux/pm.h> is no longer implicitly included.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
diff --git a/drivers/parisc/power.c b/drivers/parisc/power.c
index 6dedbde..90cca5e 100644
--- a/drivers/parisc/power.c
+++ b/drivers/parisc/power.c
@@ -41,6 +41,7 @@
 #include <linux/reboot.h>
 #include <linux/sched.h>
 #include <linux/kthread.h>
+#include <linux/pm.h>
 
 #include <asm/pdc.h>
 #include <asm/io.h>