board: rockchip: rk35xx: Add myself as reviewer to MAINTAINERS

Add myself as a reviewer for RK3566/RK3568/RK3588 boards that I have and
can help with review and testing of defconfig and device tree changes.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Acked-by: Eugen Hristev <eugen.hristev@collabora.com>
diff --git a/board/radxa/rock5a-rk3588s/MAINTAINERS b/board/radxa/rock5a-rk3588s/MAINTAINERS
index 0575026..a569efa 100644
--- a/board/radxa/rock5a-rk3588s/MAINTAINERS
+++ b/board/radxa/rock5a-rk3588s/MAINTAINERS
@@ -1,5 +1,6 @@
 ROCK5A-RK3588
 M:	Eugen Hristev <eugen.hristev@collabora.com>
+R:	Jonas Karlman <jonas@kwiboo.se>
 S:	Maintained
 F:	board/radxa/rock5a-rk3588s
 F:	include/configs/rock5a-rk3588s.h