sh: remove CONFIG_CPU_HAS_INTC_IRQ

All processor specific interrupt code is now converted to make use
of the new intc code. The config option CONFIG_CPU_HAS_INTC_IRQ is
because of that pointless.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>