package/Makefile: add C-SKY ABI variable value

In preparation for adding support for the C-SKY architecture in the
internal toolchain backend, we need to make sure that GNU_TARGET_NAME
will contain the appropriate ABI, i.e abiv1 or abiv2 depending on the
selected C-SKY core.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/Makefile.in

@@ -70,6 +70,15 @@ ABI := $(ABI)hf
 endif
 endif
 
+# For C-SKY abiv1 & abiv2
+ifeq ($(BR2_csky),y)
+ifeq ($(BR2_ck610),y)
+ABI = abiv1
+else
+ABI = abiv2
+endif
+endif
+
 # For FSL PowerPC there's SPE
 ifeq ($(BR2_powerpc_SPE),y)
 ABI = spe