arm64/sunxi: 4.6-rc1: Add dependency on generic irq chip

Commit ce3dd55b ("arm64: Introduce Allwinner SoC config option"),
added support for ARCH_SUNXI on arm64, but failed to select
GENERIC_IRQ_CHIP, which is required for drivers/irqchip/irq-sunxi-nmi.c
and causes build failures like :

  UPD     include/generated/compile.h
  CC      init/version.o
  LD      init/built-in.o
drivers/built-in.o: In function `sunxi_sc_nmi_set_type':
drivers/irqchip/irq-sunxi-nmi.c:114: undefined reference to `irq_setup_alt_chip'
drivers/built-in.o: In function `irq_domain_add_linear':
include/linux/irqdomain.h:253: undefined reference to `irq_generic_chip_ops'
include/linux/irqdomain.h:253: undefined reference to `irq_generic_chip_ops'
drivers/built-in.o: In function `sunxi_sc_nmi_irq_init':
drivers/irqchip/irq-sunxi-nmi.c:146: undefined reference to `irq_alloc_domain_generic_chips'
drivers/irqchip/irq-sunxi-nmi.c:161: undefined reference to `irq_get_domain_generic_chip'
drivers/irqchip/irq-sunxi-nmi.c:170: undefined reference to `irq_gc_mask_clr_bit'
drivers/irqchip/irq-sunxi-nmi.c:171: undefined reference to `irq_gc_mask_set_bit'
drivers/irqchip/irq-sunxi-nmi.c:172: undefined reference to `irq_gc_ack_set_bit'
drivers/irqchip/irq-sunxi-nmi.c:170: undefined reference to `irq_gc_mask_clr_bit'

Fixes: commit ce3dd55b ("arm64: Introduce Allwinner SoC config option")
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm64/Kconfig.platforms

@@ -2,6 +2,7 @@ menu "Platform selection"
 
 config ARCH_SUNXI
 	bool "Allwinner sunxi 64-bit SoC Family"
+	select GENERIC_IRQ_CHIP
 	help
 	  This enables support for Allwinner sunxi based SoCs like the A64.