MIPS: Remove get_fs/set_fs

All get_fs/set_fs calls in MIPS code are gone, so remove implementation
of it.  With the clear separation of user/kernel space access we no
longer need the EVA special handling, so get rid of that, too.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>

arch/mips/include/asm/processor.h

@@ -221,10 +221,6 @@ struct nlm_cop2_state {
 #define COP2_INIT
 #endif
 
-typedef struct {
-	unsigned long seg;
-} mm_segment_t;
-
 #ifdef CONFIG_CPU_HAS_MSA
 # define ARCH_MIN_TASKALIGN	16
 # define FPU_ALIGN		__aligned(16)