[PATCH -next] vdpa: mlx5: select VHOST to fix build errors

[Randy Dunlap <rdunlap@infradead.org>]

From: Randy Dunlap <rdunlap@infradead.org>

drivers/vdpa/mlx5/ uses vhost_iotlb*() interfaces, so select
VHOST to eliminate build errors.

ld: drivers/vdpa/mlx5/core/mr.o: in function `add_direct_chain':
mr.c:(.text+0x106): undefined reference to `vhost_iotlb_itree_first'
ld: mr.c:(.text+0x1cf): undefined reference to `vhost_iotlb_itree_next'
ld: mr.c:(.text+0x30d): undefined reference to `vhost_iotlb_itree_first'
ld: mr.c:(.text+0x3e8): undefined reference to `vhost_iotlb_itree_next'
ld: drivers/vdpa/mlx5/core/mr.o: in function `_mlx5_vdpa_create_mr':
mr.c:(.text+0x908): undefined reference to `vhost_iotlb_itree_first'
ld: mr.c:(.text+0x9e6): undefined reference to `vhost_iotlb_itree_next'
ld: drivers/vdpa/mlx5/core/mr.o: in function `mlx5_vdpa_handle_set_map':
mr.c:(.text+0xf1d): undefined reference to `vhost_iotlb_itree_first'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: netdev@vger.kernel.org
---
Note: This patch may not be the right thing, but it fixes the build errors.

 drivers/vdpa/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- linux-next-20200917.orig/drivers/vdpa/Kconfig
+++ linux-next-20200917/drivers/vdpa/Kconfig
@@ -32,6 +32,7 @@ config IFCVF
 config MLX5_VDPA
 	bool "MLX5 VDPA support library for ConnectX devices"
 	depends on MLX5_CORE
+	select VHOST
 	default n
 	help
 	  Support library for Mellanox VDPA drivers. Provides code that is