MIPS: Loongson2ef: remove orphan sbx00_acpi_init() declaration

All uses of sbx00_acpi_init() in the "pci.c" file were removed by
commit 5831fdb0 ("MIPS: Loongson2ef: clean up loongson64
related code"), so remove the orphan declaration, too.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/loongson2ef/common/pci.c

@@ -73,8 +73,6 @@ static void __init setup_pcimap(void)
 #endif
 }
 
-extern int sbx00_acpi_init(void);
-
 static int __init pcibios_init(void)
 {
 	setup_pcimap();