devres: Introduce devm_kmemdup_array()

Introduce '_array' variant of devm_kmemdup() which is more robust and
consistent with alloc family of helpers.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Author: raagjadav

include/linux/device/devres.h

@@ -79,6 +79,11 @@ void devm_kfree(struct device *dev, const void *p);
 
 void * __realloc_size(3)
 devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp);
+static inline void *devm_kmemdup_array(struct device *dev, const void *src,
+				       size_t n, size_t size, gfp_t flags)
+{
+	return devm_kmemdup(dev, src, size_mul(size, n), flags);
+}
 
 char * __malloc
 devm_kstrdup(struct device *dev, const char *s, gfp_t gfp);