powerpc/83xx: Build breakage for CONFIG_PM but no CONFIG_SUSPEND

I noticed this doing some randconfig testing (.config below).  I have
CONFIG_PM but no CONFIG_SUSPEND.  Bug is against mainline.

arch/powerpc/sysdev/built-in.o: In function `ipic_suspend':
ipic.c:(.text+0x6b34): undefined reference to `fsl_deep_sleep'
make[1]: *** [.tmp_vmlinux1] Error 1
make: *** [sub-make] Error 2

Looks like #ifdef CONFIG_PM in arch/powerpc/sysdev/ipic.c should be
CONFIG_SUSPEND.  d49747bd

 introduced
this.

Fix build when we have CONFIG_PM but no CONFIG_SUSPEND.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>