[PATCH RESEND] omap1: select GENERIC_IRQ_CHIP for TI OMAP1

Hi Axel,

Axel Lin [off-list ref] writes:

The gpio-omap driver has been converted to use generic IRQ chip.
Thus select GENERIC_IRQ_CHIP for TI OMAP1 to fix below build error.

 LD      vmlinux
drivers/built-in.o: In function `omap_mpuio_alloc_gc':
drivers/gpio/gpio-omap.c:1087: undefined reference to `irq_alloc_generic_chip'
drivers/gpio/gpio-omap.c:1100: undefined reference to `irq_setup_generic_chip'
drivers/built-in.o: In function `omap_gpio_show_rev':
drivers/gpio/gpio-omap.c:998: undefined reference to `irq_gc_mask_clr_bit'
drivers/gpio/gpio-omap.c:998: undefined reference to `irq_gc_mask_set_bit'
make: *** [vmlinux] Error 1

Signed-off-by: Axel Lin <redacted>
---
Kevin already sent a similar patch.  http://marc.info/?l=linux-omap&m=130749135312468&w=2
But I still have the build error with make omap1_defconfig in today's linux-next tree.
So here is a resend.

Tony didn't pick this up for v3.1, so I now have the original in my
fixies queue for v3.1-rc, which will be posted shortly.

Sorry this has slipped through the cracks.

Kevin