drm/nouveau/pm: fix compilation failure when CONFIG_POWER_SUPPLY is not set
drm/nouveau/pm: fix compilation failure when CONFIG_POWER_SUPPLY is not set

Signed-off-by: Martin Peres <f078f77bcd6141e84e4eefdc58402db4e0e36622@ensi-bourges.fr>
Reported-by: Stratos Psomadakis <1279c6adbafb38f35d4044d4e70c779d98ac212f@ece.ntua.gr>
Signed-off-by: Ben Skeggs <d9f27fb07c1e9f131223ad827fa5179f3846c30b@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs