mailbox: Introduce K3 Secure Proxy Driver

Secure Proxy module manages hardware threads that are meant
for communication between the processor entities. Adding
support for this driver.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 9649b70..2836ee4 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -24,4 +24,14 @@
 	  This enables support for the NVIDIA Tegra HSP Hw module, which
 	  implements doorbells, mailboxes, semaphores, and shared interrupts.
 
+config K3_SEC_PROXY
+	bool "Texas Instruments K3 Secure Proxy Driver"
+	depends on DM_MAILBOX && ARCH_K3
+	help
+	  An implementation of Secure proxy slave driver for K3 SoCs from
+	  Texas Instruments. Secure proxy is a communication entity mainly
+	  used for communication between multiple processors with the SoC.
+	  Select this driver if your platform has support for this hardware
+	  block.
+
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