exynos: update maintainer of Snow and SMDK5420 board

The email address of Rajeshwari Shinde <rajeshwari.s@samsung.com>
is not working.

This commit gives Akshay the maintainership of Snow and
SMDK5420 boards.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Akshay Saraswat <akshay.s@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

board/samsung/smdk5250/MAINTAINERS

@@ -6,7 +6,7 @@ F:	include/configs/smdk5250.h
 F:	configs/smdk5250_defconfig
 
 SNOW BOARD
-M:	Rajeshwari Shinde <rajeshwari.s@samsung.com>
+M:	Akshay Saraswat <akshay.s@samsung.com>
 S:	Maintained
 F:	include/configs/snow.h
 F:	configs/snow_defconfig

board/samsung/smdk5420/MAINTAINERS

@@ -4,9 +4,5 @@ S:	Maintained
 F:	board/samsung/smdk5420/
 F:	include/configs/peach-pit.h
 F:	configs/peach-pit_defconfig
-
-SMDK5420 BOARD
-M:	Rajeshwari Shinde <rajeshwari.s@samsung.com>
-S:	Maintained
 F:	include/configs/smdk5420.h
 F:	configs/smdk5420_defconfig