bios_emulator: fix first argument of pci_{read,write}_config_* function calls

When compiling for riscv64, a bunch of warning is produced for the file
drivers/bios_emulator/besys.c. This patch fixes a portion of those warnings,
caused by incorrect first argument to pci_{read,write}_config_* functions.

Signed-off-by: Yuri Zaporozhets <yuriz@qrv-systems.net>
diff --git a/drivers/bios_emulator/besys.c b/drivers/bios_emulator/besys.c
index 2fd794f..23392d3 100644
--- a/drivers/bios_emulator/besys.c
+++ b/drivers/bios_emulator/besys.c
@@ -49,6 +49,7 @@
 
 #define __io
 #include <asm/io.h>
+#include <pci.h>
 #include "biosemui.h"
 
 /*------------------------- Global Variables ------------------------------*/
@@ -434,32 +435,27 @@
 	if ((function == _BE_env.vgaInfo.function) &&
 	    (device == _BE_env.vgaInfo.device) &&
 	    (bus == _BE_env.vgaInfo.bus)) {
+		pci_dev_t bdf = PCI_BDF(bus, device, function);
 		switch (func) {
 		case REG_READ_BYTE:
-			pci_read_config_byte(_BE_env.vgaInfo.pcidev, regOffset,
-					     &val8);
+			pci_read_config_byte(bdf, regOffset, &val8);
 			return val8;
 		case REG_READ_WORD:
-			pci_read_config_word(_BE_env.vgaInfo.pcidev, regOffset,
-					     &val16);
+			pci_read_config_word(bdf, regOffset, &val16);
 			return val16;
 		case REG_READ_DWORD:
-			pci_read_config_dword(_BE_env.vgaInfo.pcidev, regOffset,
-					      &val32);
+			pci_read_config_dword(bdf, regOffset, &val32);
 			return val32;
 		case REG_WRITE_BYTE:
-			pci_write_config_byte(_BE_env.vgaInfo.pcidev, regOffset,
-					      value);
+			pci_write_config_byte(bdf, regOffset, value);
 
 			return 0;
 		case REG_WRITE_WORD:
-			pci_write_config_word(_BE_env.vgaInfo.pcidev, regOffset,
-					      value);
+			pci_write_config_word(bdf, regOffset, value);
 
 			return 0;
 		case REG_WRITE_DWORD:
-			pci_write_config_dword(_BE_env.vgaInfo.pcidev,
-					       regOffset, value);
+			pci_write_config_dword(bdf, regOffset, value);
 
 			return 0;
 		}