postgresql: disable spinlock support for riscv64

Fixes:
 - http://autobuild.buildroot.org/results/deebc4b8f615e1216279d6587e91f5654da2ad68

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/postgresql/postgresql.mk

@@ -34,7 +34,7 @@ ifneq ($(BR2_TOOLCHAIN_HAS_THREADS),y)
 POSTGRESQL_CONF_OPTS += --disable-thread-safety
 endif
 
-ifeq ($(BR2_arcle)$(BR2_arceb)$(BR2_microblazeel)$(BR2_microblazebe)$(BR2_or1k)$(BR2_nios2)$(BR2_xtensa),y)
+ifeq ($(BR2_arcle)$(BR2_arceb)$(BR2_microblazeel)$(BR2_microblazebe)$(BR2_or1k)$(BR2_nios2)$(BR2_riscv)$(BR2_xtensa),y)
 POSTGRESQL_CONF_OPTS += --disable-spinlocks
 endif