spl: Allow mailbox drivers to be used within SPL

Add an option for building mailbox drivers within SPL.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

common/spl/Kconfig

@@ -430,6 +430,14 @@ config SPL_LIBGENERIC_SUPPORT
 	  boards. Enable this option to build the code in lib/ as part of an
 	  SPL build.
 
+config SPL_DM_MAILBOX
+	bool "Support Mailbox"
+	help
+	  Enable support for Mailbox within SPL. This enable the inter
+	  processor communication protocols tobe used within SPL. Enable
+	  this option to build the drivers in drivers/mailbox as part of
+	  SPL build.
+
 config SPL_MMC_SUPPORT
 	bool "Support MMC"
 	depends on MMC

drivers/Makefile

@@ -14,6 +14,7 @@ obj-$(CONFIG_$(SPL_TPL_)SERIAL_SUPPORT) += serial/
 obj-$(CONFIG_$(SPL_TPL_)SPI_FLASH_SUPPORT) += mtd/spi/
 obj-$(CONFIG_$(SPL_TPL_)SPI_SUPPORT) += spi/
 obj-$(CONFIG_$(SPL_TPL_)TIMER) += timer/
+obj-$(CONFIG_$(SPL_)DM_MAILBOX) += mailbox/
 
 ifndef CONFIG_TPL_BUILD
 ifdef CONFIG_SPL_BUILD

drivers/mailbox/Makefile

@@ -2,7 +2,7 @@
 #
 # SPDX-License-Identifier: GPL-2.0
 
-obj-$(CONFIG_DM_MAILBOX) += mailbox-uclass.o
+obj-$(CONFIG_$(SPL_)DM_MAILBOX) += mailbox-uclass.o
 obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox.o
 obj-$(CONFIG_SANDBOX_MBOX) += sandbox-mbox-test.o
 obj-$(CONFIG_TEGRA_HSP) += tegra-hsp.o