co-maintainance of remoteproc/rpmsg/hwspinlock

[Ohad Ben-Cohen]

Hi everyone,

Due to lack of time in the next few months, I've asked Bjorn Andersson for
help with the remoteproc/rpmsg/hwspinlock maintainership.

Bjorn has kindly agreed to step up and co-maintain
remoteproc/rpmsg/hwspinlock with me, and we expect that Bjorn will start
picking up patches as soon as the next development cycle begins.

Bjorn, thanks so much and please feel free to send a MAINTAINERS patch
adding yourself as a maintainer for these three subsystems.

I will still be available for any assistance or questions,

Best wishes,
Ohad.