dm: SMEM (Shared memory) uclass

This is a uclass for Shared memory manager drivers.

A Shared Memory Manager driver implements an interface for allocating
and accessing items in the memory area shared among all of the
processors.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/drivers/Makefile b/drivers/Makefile
index 66834c3..276e5ee 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -98,6 +98,7 @@
 obj-y += reset/
 obj-y += input/
 # SOC specific infrastructure drivers.
+obj-y += smem/
 obj-y += soc/
 obj-$(CONFIG_REMOTEPROC) += remoteproc/
 obj-y += thermal/