fpga: Change the first parameter in fpga_loadbitstream

All fpga functions use devnum as int. Only fpga_loadbitstream
is using it as unsinged long dev.
This patch synchronize it.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/drivers/fpga/fpga.c b/drivers/fpga/fpga.c
index f0253bf..244f503 100644
--- a/drivers/fpga/fpga.c
+++ b/drivers/fpga/fpga.c
@@ -190,7 +190,7 @@
 /*
  * Convert bitstream data and load into the fpga
  */
-int __weak fpga_loadbitstream(unsigned long dev, char *fpgadata, size_t size)
+int __weak fpga_loadbitstream(int devnum, char *fpgadata, size_t size)
 {
 	printf("Bitstream support not implemented for this FPGA device\n");
 	return FPGA_FAIL;