ia64: define ioremap_uc()

All architectures now need ioremap_uc(), ia64 seems defines this already
through its ioremap_nocache() and it already ensures it *only* uses UC.

This is needed since v4.3 to complete an allyesconfig compile on ia64,
there were others archs that needed this, and this one seems to have
fallen through the cracks.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>	[4.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>