MAINTAINERS: Add an entry for common Renesas peripherals

Renesas peripherals are common to SH4/RX based MCUs. Their
datasheets share common sections. It makes sense to maintain
them altogether.
Add the uncovered UART SCI peripheral.
The current names are misleading (see the 'sh_' prefix).
In another series we will remove these peripherals with
the 'renesas_' prefix. Out of the scope of this change in
MAINTAINERS.

Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

MAINTAINERS

@@ -1264,7 +1264,6 @@ R: Magnus Damm <magnus.damm@gmail.com>
 S: Maintained
 F: hw/sh4/r2d.c
 F: hw/intc/sh_intc.c
-F: hw/timer/sh_timer.c
 F: include/hw/sh4/sh_intc.h
 
 Shix
@@ -1968,6 +1967,14 @@ F: hw/*/*xive*
 F: include/hw/*/*xive*
 F: docs/*/*xive*
 
+Renesas peripherals
+M: Yoshinori Sato <ysato@users.sourceforge.jp>
+R: Magnus Damm <magnus.damm@gmail.com>
+S: Maintained
+F: hw/char/sh_serial.c
+F: hw/timer/sh_timer.c
+F: include/hw/sh4/sh.h
+
 Subsystems
 ----------
 Audio