cr50: enable use malloc/free
In preparation to adding new features, switch cr50 to using shared
memory allocator allowing concurrently allocated buffers.
BRANCH=none
TEST=verified that cr50 works fine and could be updated on a reef.
/* Go to sleep when nothing else is happening */
#define CONFIG_LOW_POWER_IDLE
+/* Allow multiple concurrent memory allocations. */
+#define CONFIG_MALLOC
+
/* Detect the states of other devices */
#define CONFIG_DEVICE_STATE
