MAINTAINERS: Add gd32 platform
MAINTAINERS: Add gd32 platform

Add nandojve as GigaDevice maintainer and gmarull as co-maintainer.

Signed-off-by: Gerson Fernando Budke <de7eb9f159f7e30f8dcdecee89db6e1a285bf5b2@atl-electronics.com>

zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr