[SPARC64]: Fix sparse warnings wrt. machine_alt_power_off().

arch/sparc64/kernel/process.c:123:6: warning: symbol 'machine_alt_power_off' was not declared. Should it be static?

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c
index 6eceac5..75c1408 100644
--- a/arch/sparc64/kernel/process.c
+++ b/arch/sparc64/kernel/process.c
@@ -47,6 +47,7 @@
 #include <asm/unistd.h>
 #include <asm/hypervisor.h>
 #include <asm/sstate.h>
+#include <asm/reboot.h>
 
 /* #define VERBOSE_SHOWREGS */