arm64: Kconfig: select HISILICON_IRQ_MBIGEN only if PCI is selected

Even when PCI is disabled, ARCH_HISI selects HISILICON_IRQ_MBIGEN
triggerring the following config warning:

warning: (ARM64 && HISILICON_IRQ_MBIGEN) selects ARM_GIC_V3_ITS which
	has unmet direct dependencies (PCI && PCI_MSI)

This patch makes selection of HISILICON_IRQ_MBIGEN conditional on PCI.

Cc: Ma Jun <majun258@huawei.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
index fd3ee3a..be5d824 100644
--- a/arch/arm64/Kconfig.platforms
+++ b/arch/arm64/Kconfig.platforms
@@ -66,7 +66,7 @@
 config ARCH_HISI
 	bool "Hisilicon SoC Family"
 	select ARM_TIMER_SP804
-	select HISILICON_IRQ_MBIGEN
+	select HISILICON_IRQ_MBIGEN if PCI
 	help
 	  This enables support for Hisilicon ARMv8 SoC family