MAINTAINERS: add entry for Samsung Exynos mailbox driver

Add entry for the Samsung Exynos mailbox driver.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

Author: ambarus

MAINTAINERS

@@ -3020,6 +3020,7 @@ F:	drivers/*/*s3c24*
 F:	drivers/*/*s3c64xx*
 F:	drivers/*/*s5pv210*
 F:	drivers/clocksource/samsung_pwm_timer.c
+F:	drivers/mailbox/exynos-mailbox.c
 F:	drivers/memory/samsung/
 F:	drivers/pwm/pwm-samsung.c
 F:	drivers/soc/samsung/
@@ -20712,6 +20713,15 @@ F:	arch/arm64/boot/dts/exynos/exynos850*
 F:	drivers/clk/samsung/clk-exynos850.c
 F:	include/dt-bindings/clock/exynos850.h
 
+SAMSUNG EXYNOS MAILBOX DRIVER
+M:	Tudor Ambarus <tudor.ambarus@linaro.org>
+L:	linux-kernel@vger.kernel.org
+L:	linux-samsung-soc@vger.kernel.org
+S:	Supported
+F:	Documentation/devicetree/bindings/mailbox/google,gs101-mbox.yaml
+F:	drivers/mailbox/exynos-mailbox.c
+F:	include/linux/mailbox/exynos-message.h
+
 SAMSUNG EXYNOS PSEUDO RANDOM NUMBER GENERATOR (RNG) DRIVER
 M:	Krzysztof Kozlowski <krzk@kernel.org>
 L:	linux-crypto@vger.kernel.org