Libva-utils 2.15.0

• add: Added HDR10 Tone Mapping sample code including H2H and H2S config files.
• add: Support lowpower for HEVC Encoding
• fix: Set correct entrypoint for lowpower
• fix: Components exceed the value specified by jpeg spec
• fix: hdr local variable pointer access issue
• fix: Fix issue incorrect color for EU based hevcencode
• fix: exclude vgem node and invalid drm node in vainfo
• ci:Disable travis build
• meson: check the dependency of libdrm