MAINTAINERS: update arm64 Microchip entries

Krzysztof noticed that patches for arch/arm64/boot/dts/microchip were
getting lost & the listed tree was inactive.

Nicolas and I are willing to shepherd patches to Arnd, using the
existing at91 tree, so add a new entry covering
arch/arm64/boot/dts/microchip, listing us as maintainers.

Drop the tree from the existing sparx5 entry & narrow the devicetree
pattern to just sparx devices, leaving Lars, Steen and Daniel looking
after support for their SoCs.

CC: Rob Herring <[email protected]>
CC: Krzysztof Kozlowski <[email protected]>
CC: Conor Dooley <[email protected]>
CC: Nicolas Ferre <[email protected]>
CC: Claudiu Beznea <[email protected]>
CC: [email protected]
CC: Lars Povlsen <[email protected]>
CC: Steen Hegelund <[email protected]>
CC: Daniel Machon <[email protected]>
Signed-off-by: Conor Dooley <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
Acked-by: Steen Hegelund <[email protected]>
Acked-by: Claudiu Beznea <[email protected]>
Link: https://lore.kernel.org/r/20230522-wagon-stencil-a164ec39322a@wendy
Signed-off-by: Arnd Bergmann <[email protected]>

Author: ConchuOD

MAINTAINERS

@@ -2429,15 +2429,23 @@ X:	drivers/net/wireless/atmel/
 N:	at91
 N:	atmel
 
+ARM/MICROCHIP (ARM64) SoC support
+M:	Conor Dooley <[email protected]>
+M:	Nicolas Ferre <[email protected]>
+M:	Claudiu Beznea <[email protected]>
+L:	[email protected] (moderated for non-subscribers)
+S:	Supported
+T:	git https://git.kernel.org/pub/scm/linux/kernel/git/at91/linux.git
+F:	arch/arm64/boot/dts/microchip/
+
 ARM/Microchip Sparx5 SoC support
 M:	Lars Povlsen <[email protected]>
 M:	Steen Hegelund <[email protected]>
 M:	Daniel Machon <[email protected]>
 M:	[email protected]
 L:	[email protected] (moderated for non-subscribers)
 S:	Supported
-T:	git git://github.com/microchip-ung/linux-upstream.git
-F:	arch/arm64/boot/dts/microchip/
+F:	arch/arm64/boot/dts/microchip/sparx*
 F:	drivers/net/ethernet/microchip/vcap/
 F:	drivers/pinctrl/pinctrl-microchip-sgpio.c
 N:	sparx5