arm: mvebu: Remove unused ARMADA_64BIT

Nothing selects ARMADA_64BIT. Instead the 64-bit SoCs just select ARM64
directly. Remove the unused config item.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig
index a3f273f..c764439 100644
--- a/arch/arm/mach-mvebu/Kconfig
+++ b/arch/arm/mach-mvebu/Kconfig
@@ -17,10 +17,6 @@
 	select TRANSLATION_OFFSET
 	select SPL_SYS_NO_VECTOR_TABLE if SPL
 
-config ARMADA_64BIT
-	bool
-	select ARM64
-
 # ARMv7 SoCs...
 config ARMADA_375
 	bool