UBUNTU: SAUCE: (snapdragon) PM / OPP: Add a helper to get an opp regulator for device

UBUNTU: SAUCE: (snapdragon) PM / OPP: Add a helper to get an opp regulator for device

BugLink: http://bugs.launchpad.net/bugs/1763040
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
(cherry picked from commit 0482a1c2fd22ac6d6898fd0f42e846c74d5d6c5e
http://git.linaro.org/landing-teams/working/qualcomm/kernel.git release/qcomlt-4.14)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>