iop: enable generic time

This updates the IOP platform to use the kernel's generic time
framework. With clockevent support in place, this reduces to
selecting GENERIC_TIME and removing the platform's private timer
->offset() operation (iop_gettimeoffset).

Tested on n2100, compile-tested for all plat-iop machines.

Signed-off-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

arch/arm/include/asm/hardware/iop3xx.h

@@ -234,7 +234,6 @@ extern int iop3xx_get_init_atu(void);
 void iop3xx_map_io(void);
 void iop_init_cp6_handler(void);
 void iop_init_time(unsigned long tickrate);
-unsigned long iop_gettimeoffset(void);
 
 static inline u32 read_tmr0(void)
 {