anv: Rename get_image_format_properties()

anv: Rename get_image_format_properties()

The name is misleading. It looks like vkGetPhysicalDeviceImageFormatProperties(),
but it actually implement vkGetPhysicalDeviceFormatProperties. Let's
rename it to what it actually does, get_image_format_features(), because it
returns VkFormatFeatureFlags.

For consistency, also rename get_buffer_format_properties() to
get_buffer_format_features().

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>