MAINTAINERS: Add stm32 remoteproc driver

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index bc67c49..2f334fc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -311,6 +311,7 @@
 F:	drivers/power/regulator/stm32-vrefbuf.c
 F:	drivers/power/regulator/stpmic1.c
 F:	drivers/ram/stm32mp1/
+F:	drivers/remoteproc/stm32_copro.c
 F:	drivers/misc/stm32_rcc.c
 F:	drivers/reset/stm32-reset.c
 F:	drivers/spi/stm32_qspi.c