amdfam10: Fix mismatch of function declarations

Callsite declared returning int, which makes more sense
than u8 the motherboard side code defined the functions
with.

Change-Id: I8ee83aa2833408ad163c9011a076e08578f3ca6f
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/26774
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

src/southbridge/amd/rs780/gfx.c

@@ -35,7 +35,7 @@
 #include <delay.h>
 #include <cpu/x86/msr.h>
 #include "rs780.h"
-extern int is_dev3_present(void);
+
 void set_pcie_reset(void);
 void set_pcie_dereset(void);
 

src/southbridge/amd/rs780/rs780.h

@@ -222,5 +222,6 @@ int is_family10h(void);
 void enable_rs780_dev8(void);
 void rs780_early_setup(void);
 void rs780_htinit(void);
+int is_dev3_present(void);
 
 #endif /* __RS780_H__ */