MAINTAINERS: remove SPEAR entry

As the lastest spear directories are removed, delete the associated entry
in the MAINTAINERS file:
- arch/arm/cpu/arm926ejs/spear/
- arch/arm/include/asm/arch-spear/

Fixes: 570c3dcfc153 ("arm: Remove spear600 boards and the rest of SPEAr support")
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 67c96a6..5370b55 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -412,13 +412,6 @@
 F:	include/dt-bindings/clock/stih410-clks.h
 F:	include/dt-bindings/reset/stih407-resets.h
 
-ARM STM SPEAR
-#M:	Vipin Kumar <vipin.kumar@st.com>
-S:	Orphaned (Since 2016-02)
-T:	git https://source.denx.de/u-boot/custodians/u-boot-stm.git
-F:	arch/arm/cpu/arm926ejs/spear/
-F:	arch/arm/include/asm/arch-spear/
-
 ARM STM STM32MP
 M:	Patrick Delaunay <patrick.delaunay@foss.st.com>
 M:	Patrice Chotard <patrice.chotard@foss.st.com>