Update the binding for two more PMICs supported by the same driver.
While we're here, remove the duplicate pmi8994 lines because that
support got merged twice.

Cc: Rajendra Nayak <rnayak@codeaurora.org>
Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>