MAINTAINERS: adjust PISTACHIO SOC SUPPORT after its retirement

Commit 104f942b ("MIPS: Retire MACH_PISTACHIO") removes
./arch/mips/pistachio/ and ./arch/mips/configs/pistachio_defconfig, but
misses to adjust the corresponding section PISTACHIO SOC SUPPORT
in MAINTAINERS.

Hence, ./scripts/get_maintainer.pl --self-test=patterns complains:

  warning: no file matches    F:    arch/mips/configs/pistachio*_defconfig
  warning: no file matches    F:    arch/mips/pistachio/

As James Hartley is not reachable with the provided email address, the
remaining dtsi file, arch/mips/boot/dts/img/pistachio.dtsi, must be
maintained by its only user pistachio_marduk.dts, which is part of MARDUK
(CREATOR CI40) DEVICE TREE SUPPORT.

Add maintenance of pistachio.dtsi to that section and drop the PISTACHIO
SOC SUPPORT after its retirement.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Rahul Bedarkar <rahulbedarkar89@gmail.com>
Acked-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MAINTAINERS

@@ -11039,7 +11039,7 @@ MARDUK (CREATOR CI40) DEVICE TREE SUPPORT
 M:	Rahul Bedarkar <rahulbedarkar89@gmail.com>
 L:	linux-mips@vger.kernel.org
 S:	Maintained
-F:	arch/mips/boot/dts/img/pistachio_marduk.dts
+F:	arch/mips/boot/dts/img/pistachio*
 
 MARVELL 88E6XXX ETHERNET SWITCH FABRIC DRIVER
 M:	Andrew Lunn <andrew@lunn.ch>
@@ -14694,14 +14694,6 @@ S:	Maintained
 W:	http://www.st.com/spear
 F:	drivers/pinctrl/spear/
 
-PISTACHIO SOC SUPPORT
-M:	James Hartley <james.hartley@sondrel.com>
-L:	linux-mips@vger.kernel.org
-S:	Odd Fixes
-F:	arch/mips/boot/dts/img/pistachio*
-F:	arch/mips/configs/pistachio*_defconfig
-F:	arch/mips/pistachio/
-
 PKTCDVD DRIVER
 M:	linux-block@vger.kernel.org
 S:	Orphan