remove Broadcom Northstar 2 Target entry

The Broadcom Northstar 2 support was removed when the
bcm958712k board was removed but the target entry was
missed so clean that up as well.

Fixes: d59bc09d829 ("arm: Remove bcm958712k board")
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index c7c236b..65fa7ba 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -699,15 +699,6 @@
 	  ARMv7 Cortex-A9 SoC family including BCM4708, BCM47094,
 	  BCM5301x etc.
 
-config TARGET_BCMNS2
-	bool "Support Broadcom Northstar2"
-	select ARM64
-	select GPIO_EXTRA_HEADER
-	help
-	  Support for Broadcom Northstar 2 SoCs.  NS2 is a quad-core 64-bit
-	  ARMv8 Cortex-A57 processors targeting a broad range of networking
-	  applications.
-
 config TARGET_BCMNS3
 	bool "Support Broadcom NS3"
 	select ARM64