powerpc/qe: Implement qe_alive_during_sleep() helper function

In some CPUs (i.e. MPC8569) QE shuts down completely during sleep,
drivers may want to know that to reinitialize registers and buffer
descriptors.

This patch implements qe_alive_during_sleep() helper function, so far
it just checks if MPC8569-compatible power management controller is
present, which is a sign that QE turns off during sleep.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/powerpc/include/asm/qe.h b/arch/powerpc/include/asm/qe.h
index 157c5ca..f388f0a 100644
--- a/arch/powerpc/include/asm/qe.h
+++ b/arch/powerpc/include/asm/qe.h
@@ -154,6 +154,7 @@
 void qe_put_snum(u8 snum);
 unsigned int qe_get_num_of_risc(void);
 unsigned int qe_get_num_of_snums(void);
+int qe_alive_during_sleep(void);
 
 /* we actually use cpm_muram implementation, define this for convenience */
 #define qe_muram_init cpm_muram_init