qemu-nios2: use glibc

newlib fails to compile for nios2 architecture.  Work around this by
using glibc instead.

Signed-off-by: Jon Mason <jon.mason@arm.com>
Signed-off-by: Naveen Saini <naveen.kumar.saini@intel.com>

meta-zephyr-bsp/conf/machine/qemu-nios2.conf

@@ -14,3 +14,5 @@ QB_OPT_APPEND = "-nographic"
 QB_CPU = "-cpu nios2"
 
 ARCH:qemu-nios2 = "nios2"
+
+TCLIBC = "glibc"

meta-zephyr-core/conf/distro/zephyr.conf

@@ -4,7 +4,7 @@ DISTRO_VERSION = "1.0"
 
 TARGET_VENDOR = "-yocto"
 
-TCLIBC = "newlib"
+TCLIBC ?= "newlib"
 
 TEST_TARGET = "QemuTargetZephyr"
 TEST_SUITES = "zephyr"