arm/scp-firmware: oe_runmake already passes EXTRA_OEMAKE

oe_runmake adds EXTRA_OEMAKE to the arguments, so there's no need to do
it again.

Change-Id: Id8f078faecba72156a4626c960fc7113a70c8eba
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

meta-arm/recipes-bsp/scp-firmware/scp-firmware_git.bb

@@ -66,7 +66,7 @@ EXTRA_OEMAKE = "${SCP_COMP_STR} \
                 "
 
 do_compile() {
-    oe_runmake -C "${S}" ${EXTRA_OEMAKE}
+    oe_runmake -C "${S}"
 }
 do_compile[cleandirs] += "${B}"