lz4: disable static library on shared only

Don't build the static library when BR2_SHARED_LIBS=y, to reduce build
time.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/lz4/lz4.mk

@@ -12,6 +12,8 @@ LZ4_LICENSE_FILES = lib/LICENSE programs/COPYING
 
 ifeq ($(BR2_STATIC_LIBS),y)
 LZ4_MAKE_OPTS += BUILD_SHARED=no
+else ifeq ($(BR2_SHARED_LIBS),y)
+LZ4_MAKE_OPTS += BUILD_STATIC=no
 endif
 
 define HOST_LZ4_BUILD_CMDS