pico-imx6ul: MAINTAINERS: Unify all board entries

It is easier to consolidate all boards into a single entry.

Signed-off-by: Fabio Estevam <festevam@gmail.com>

board/technexion/pico-imx6ul/MAINTAINERS

@@ -5,13 +5,5 @@ S:	Maintained
 F:	board/technexion/pico-imx6ul/
 F:	include/configs/pico-imx6ul.h
 F:	configs/pico-imx6ul_defconfig
-
-TechNexion PICO-HOBBIT-IMX6UL
-M:	Otavio Salvador <otavio@ossystems.com.br>
-S:	Maintained
 F:	configs/pico-hobbit-imx6ul_defconfig
-
-TechNexion PICO-PI-IMX6UL
-M:	Otavio Salvador <otavio@ossystems.com.br>
-S:	Maintained
 F:	configs/pico-pi-imx6ul_defconfig