drivers: net: xgene: Remove unnecessary forward declarations

Clang warns:

drivers/net/ethernet/apm/xgene/xgene_enet_main.c:33:36: warning:
tentative array definition assumed to have one element
static const struct acpi_device_id xgene_enet_acpi_match[];
                                   ^
1 warning generated.

Both xgene_enet_acpi_match and xgene_enet_of_match are defined before
their uses at the bottom of the file so this is unnecessary. When
CONFIG_ACPI is disabled, ACPI_PTR becomes NULL so xgene_enet_acpi_match
doesn't need to be defined.
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/apm/xgene/xgene_enet_main.c

@@ -29,9 +29,6 @@
 #define RES_RING_CSR	1
 #define RES_RING_CMD	2
 
-static const struct of_device_id xgene_enet_of_match[];
-static const struct acpi_device_id xgene_enet_acpi_match[];
-
 static void xgene_enet_init_bufpool(struct xgene_enet_desc_ring *buf_pool)
 {
 	struct xgene_enet_raw_desc16 *raw_desc;