remoteproc: Introduce Qualcomm ADSP PIL

The Qualcomm ADSP Peripheral Image Loader is used on a variety of
different Qualcomm platforms for loading firmware into and controlling
the Hexagon based ADSP.

Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>