depends: Compile bdb with --disable-atomics on aarch64

This sidesteps the problem where the atomics check tries to run a test
binary, which cannot be performed during cross compilation. We should
replace this with a better solution in future.

Part of #3710.

depends/packages/bdb.mk

@@ -9,6 +9,7 @@ define $(package)_set_vars
 $(package)_config_opts=--disable-shared --enable-cxx --disable-replication
 $(package)_config_opts_mingw32=--enable-mingw
 $(package)_config_opts_linux=--with-pic
+$(package)_config_opts_aarch64=--disable-atomicsupport
 $(package)_cxxflags=-std=c++11
 endef