mogami: remove undervolt options from Kconfig

with this change we're able to disable undervolt only by changing the defconfigs

Change-Id: I19e0111ee250c1ee2d7b2305366ce5727ef2ff34
Signed-off-by: Michael Bestas <mikeioannina@gmail.com>
Merge pull request #31 from mikeNG/undervolt

mogami: remove undervolt options from Kconfig