MIPS: lantiq: remove unused function declaration

The removed function declaration is a leftover of the old gphy firmware
loader, that has been removed in d5103604.
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h

@@ -94,9 +94,6 @@ extern __iomem void *ltq_cgu_membase;
 #define LTQ_MPS_BASE_ADDR	(KSEG1 + 0x1F107000)
 #define LTQ_MPS_CHIPID		((u32 *)(LTQ_MPS_BASE_ADDR + 0x0344))
 
-/* allow booting xrx200 phys */
-int xrx200_gphy_boot(struct device *dev, unsigned int id, dma_addr_t dev_addr);
-
 /* request a non-gpio and set the PIO config */
 #define PMU_PPE			 BIT(13)
 extern void ltq_pmu_enable(unsigned int module);