gmp: add explicit dependencies for host variant

Signed-off-by: Julien Floret <julien.floret@6wind.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gmp/gmp.mk

@@ -11,6 +11,7 @@ GMP_INSTALL_STAGING = YES
 GMP_LICENSE = LGPLv3+
 GMP_LICENSE_FILES = COPYING.LESSERv3
 GMP_DEPENDENCIES = host-m4
+HOST_GMP_DEPENDENCIES = host-m4
 
 # GMP doesn't support assembly for coldfire or mips r6 ISA yet
 ifeq ($(BR2_m68k_cf)$(BR2_mips_32r6)$(BR2_mips_64r6),y)