UBUNTU: [Config] Enabled XGENE_SLIMPRO_MBOX as a module

Signed-off-by: Craig Magina <craig.magina@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

debian.master/config/config.common.ubuntu

@@ -9053,6 +9053,7 @@ CONFIG_XFS_QUOTA=y
 CONFIG_XFS_RT=y
 # CONFIG_XFS_WARN is not set
 CONFIG_XGENE_DMA=m
+CONFIG_XGENE_SLIMPRO_MBOX=m
 CONFIG_XILINX_EMACLITE=m
 CONFIG_XILINX_LL_TEMAC=m
 CONFIG_XILLYBUS_OF=m