megasas: disable due to build breakage

The Buildbot has detected a new failure on builder default_i386_rhel61 while
building qemu.

Full details are available at:
 http://buildbot.b1-systems.de/qemu/builders/default_i386_rhel61/builds/304

The proper fix is non-trivial so let's disable the build by default until it's
fixed properly.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/default-configs/pci.mak b/default-configs/pci.mak
index 4b49c00..9d3e1db 100644
--- a/default-configs/pci.mak
+++ b/default-configs/pci.mak
@@ -10,7 +10,6 @@
 CONFIG_PCNET_PCI=y
 CONFIG_PCNET_COMMON=y
 CONFIG_LSI_SCSI_PCI=y
-CONFIG_MEGASAS_SCSI_PCI=y
 CONFIG_RTL8139_PCI=y
 CONFIG_E1000_PCI=y
 CONFIG_IDE_CORE=y