drm/msm-lease: create DRM MSM LEASE driver

Currently one DRM device only registers one card at /dev/dri/card0 and
can only support one file opened as master at a time. This change will
create /dev/dri/card<n>, n=1,2,..., from dtsi file, to allow each card
share the same DRM device but behaves as there are multiple virtual
DRM devices.

The DRM MSM LEASE driver is built based on the concept of DRM lease, but
instead of leasing from IOCTL, this driver does implicitly leasing through
card open and virtualizes each lessee as different DRM devices. With this
change, user can open and operate on each card independently just as
there are multiple DPUs in the system.

Change-Id: I9a9d56c1c40f09a9fad7dfd27f973f270f404afe
Signed-off-by: Xiaowen Wu <wxiaowen@codeaurora.org>