MAINTAINERS: add myself as maintainer for spi-fsl-dspi driver

Since I've introduced a fairly large diff to this driver since tag v5.4,
I would like to avoid breakage for my use cases by getting a chance to
be copied on newly submitted patches.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20200821213753.3143632-1-olteanv@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

MAINTAINERS

@@ -6806,6 +6806,14 @@ L:	linuxppc-dev@lists.ozlabs.org
 S:	Maintained
 F:	drivers/dma/fsldma.*
 
+FREESCALE DSPI DRIVER
+M:	Vladimir Oltean <olteanv@gmail.com>
+L:	linux-spi@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/spi/spi-fsl-dspi.txt
+F:	drivers/spi/spi-fsl-dspi.c
+F:	include/linux/spi/spi-fsl-dspi.h
+
 FREESCALE ENETC ETHERNET DRIVERS
 M:	Claudiu Manoil <claudiu.manoil@nxp.com>
 L:	netdev@vger.kernel.org