pico-imx7d: 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-imx7d/MAINTAINERS

 TechNexion PICO-IMX7D board
 M:	Vanessa Maegima <vanessa.maegima@nxp.com>
+M:	Otavio Salvador <otavio@ossystems.com.br>
 S:	Maintained
 F:	board/technexion/pico-imx7d/
 F:	include/configs/pico-imx7d.h
 F:	configs/pico-imx7d_defconfig
-
-TechNexion PICO-HOBBIT-IMX7
-M:	Otavio Salvador <otavio@ossystems.com.br>
-S:	Maintained
+F:	configs/pico-imx7d_bl33_defconfig
 F:	configs/pico-hobbit-imx7d_defconfig
-
-TechNexion PICO-PI-IMX7
-M:	Otavio Salvador <otavio@ossystems.com.br>
-S:	Maintained
 F:	configs/pico-pi-imx7d_defconfig