hw: misc, add educational driver

I am using qemu for teaching the Linux kernel at our university. I
wrote a simple PCI device that can answer to writes/reads, generate
interrupts and perform DMA. As I am dragging it locally over 2 years,
I am sending it to you now.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
[Fix 32-bit compilation. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/default-configs/pci.mak b/default-configs/pci.mak
index a186c39..030cdc7 100644
--- a/default-configs/pci.mak
+++ b/default-configs/pci.mak
@@ -32,3 +32,4 @@
 CONFIG_NVME_PCI=y
 CONFIG_SD=y
 CONFIG_SDHCI=y
+CONFIG_EDU=y