Add the generic compatible strings for the PMIC gpio and MPP
modules found on qcom based PMICs.

Cc: <devicetree@vger.kernel.org>
Cc: "Ivan T. Ivanov" <iivanov@mm-sol.com>
Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Andy Gross <agross@codeaurora.org>