MIPS: ath25: add board configuration detection

All boards based on AR5312/AR2315 SoC have a special structure located
at the end of flash. This structure contains board-specific data such as
Ethernet and Wireless MAC addresses. The flash is mapped to the memmory
at predefined location.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Linux MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8243/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ath25/ar5312.h b/arch/mips/ath25/ar5312.h
index 86dfc6d..470abb0 100644
--- a/arch/mips/ath25/ar5312.h
+++ b/arch/mips/ath25/ar5312.h
@@ -4,6 +4,7 @@
 #ifdef CONFIG_SOC_AR5312
 
 void ar5312_arch_init_irq(void);
+void ar5312_init_devices(void);
 void ar5312_plat_time_init(void);
 void ar5312_plat_mem_setup(void);
 void ar5312_arch_init(void);
@@ -11,6 +12,7 @@
 #else
 
 static inline void ar5312_arch_init_irq(void) {}
+static inline void ar5312_init_devices(void) {}
 static inline void ar5312_plat_time_init(void) {}
 static inline void ar5312_plat_mem_setup(void) {}
 static inline void ar5312_arch_init(void) {}