Fix VPP DPDK build failure with Mellanox NIC on aarch64
This compile issue was first reported by Sirshak Das in following thread:
The issue was caused by auto-config shell script auto-config-h.sh regard
quotation mark "" as $CROSS prefix for $CC when CROSS is empty.
@@ -80,7 +80,8 @@ DPDK_TUNE ?= core-avx2
# ARM64
##############################################################################
else ifeq ($(MACHINE),aarch64)
-export CROSS=""
+CROSS :=
+export CROSS
DPDK_TARGET ?= arm64-armv8a-linuxapp-$(DPDK_CC)
DPDK_MACHINE ?= armv8a
DPDK_TUNE ?= generic
