ARM: kirkwood: remove obsolete call to icache_enable

ARM: kirkwood: remove obsolete call to icache_enable

Commit a54d18a433ea ("ARM: CPU: arm926ejs: Consolidate cache routines to
common file") changed cache setup for Kirkwood such that icache_enable()
is now called from enable_caches() which is called from initr_caches()
which is in the list of functions in init_sequence_r[] prior to
arch_misc_init().  This means the call to icache_enable() in
arch_misc_init() is no longer required, so remove it.

Signed-off-by: Leigh Brown <leigh@solinno.co.uk>
Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>