lan743x: make functions lan743x_csr_read and lan743x_csr_read static

Functions lan743x_csr_read and lan743x_csr_read are local to the source
and do not need to be in global scope, so make them static.

Cleans up sparse warning:
drivers/net/ethernet/microchip/lan743x_main.c:56:5: warning: symbol
lan743x_csr_read' was not declared. Should it be static?
drivers/net/ethernet/microchip/lan743x_main.c:61:6: warning: symbol
'lan743x_csr_write' was not declared. Should it be static?

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/lan743x_main.c

@@ -53,12 +53,13 @@ return_error:
 	return ret;
 }
 
-u32 lan743x_csr_read(struct lan743x_adapter *adapter, int offset)
+static u32 lan743x_csr_read(struct lan743x_adapter *adapter, int offset)
 {
 	return ioread32(&adapter->csr.csr_address[offset]);
 }
 
-void lan743x_csr_write(struct lan743x_adapter *adapter, int offset, u32 data)
+static void lan743x_csr_write(struct lan743x_adapter *adapter, int offset,
+			      u32 data)
 {
 	iowrite32(data, &adapter->csr.csr_address[offset]);
 }