Enable binder and ashmem modules

Anbox is a free and open-source compatibility layer that aims to allow
mobile applications and mobile games developed for Android to run on
GNU/Linux distributions.

The application needs binder and ashmem modules to work. The project
used to provide dkms modules alongside the application itself. The dkms
modules, however, are not compatible with kernel versions 5.7.0+. So to
be able to use anbox one needs to compile the modules which exist in
kernel tree.

It's seems a good idea to compile the modules for 5.7.0+ kernels.

close #16

config-fragment

@@ -3999,3 +3999,9 @@ CONFIG_ZSWAP_COMPRESSOR_DEFAULT="zstd"
 CONFIG_ZSWAP_ZPOOL_DEFAULT="zbud"
 # CONFIG_ZSWAP_ZPOOL_DEFAULT_Z3FOLD is not set
 # CONFIG_ZSWAP_ZPOOL_DEFAULT_ZSMALLOC is not set
+CONFIG_ASHMEM=y
+CONFIG_ANDROID=y
+CONFIG_ANDROID_BINDER_IPC=y
+CONFIG_ANDROID_BINDERFS=y
+CONFIG_ANDROID_BINDER_DEVICES="binder,hwbinder,vndbinder"
+# CONFIG_ANDROID_BINDER_IPC_SELFTEST is not set