MAINTAINERS: update entries for ARM/STM32

Changes old git repository to the maintained one and adds more patterns.

Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>
Acked-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
1 file changed