MIPS: Lantiq: Fix build failure

MIPS: Lantiq: Fix build failure

Some configs of mips like xway_defconffig are failing with the error:
arch/mips/lantiq/irq.c:209:2: error: initialization from incompatible
pointer type [-Werror]
  "icu",
  ^
arch/mips/lantiq/irq.c:209:2: error: (near initialization for
'ltq_irq_type.parent_device') [-Werror]
arch/mips/lantiq/irq.c:219:2: error: initialization from incompatible
pointer type [-Werror]
  "eiu",
  ^
arch/mips/lantiq/irq.c:219:2: error: (near initialization for
'ltq_eiu_type.parent_device') [-Werror]

The first member of the "struct irq" is no longer a pointer for the
name.

Fixes: be45beb2df69 ("genirq: Add runtime power management support for IRQ chips")
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Acked-by: John Crispin <john@phrozen.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13684/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>