driver-core: platform: Add platform_irq_count()

A recent patch added calls to of_irq_count() in the qcom pinctrl
drivers and that caused module build failures because
of_irq_count() is not an exported symbol. We shouldn't export
of_irq_count() to modules because it's an internal OF API that
shouldn't be used by drivers. Platform drivers should use
platform device APIs instead. Therefore, add a platform_irq_count()
API that mirrors the of_irq_count() API so that platform drivers
can stay DT agnostic.

Cc: Andy Gross <andy.gross@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index dc777be..6abd019 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -51,6 +51,7 @@
 extern struct resource *platform_get_resource(struct platform_device *,
 					      unsigned int, unsigned int);
 extern int platform_get_irq(struct platform_device *, unsigned int);
+extern int platform_irq_count(struct platform_device *);
 extern struct resource *platform_get_resource_byname(struct platform_device *,
 						     unsigned int,
 						     const char *);