xf86drm: Update drmGetFormatModifierNameFromArm to handle AFRC

Update drmGetFormatModifierNameFromArm function to handle AFRC
modifiers.

Signed-off-by: Dennis Tsiang <dennis.tsiang@arm.com>
6 jobs for main in 35 seconds (queued for 12 seconds)
Status Name Job ID Coverage
  Containers
passed debian #14321409

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  Build
passed meson-aarch64 #14321412

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passed meson-armhf #14321413

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passed meson-i386 #14321411

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passed meson-ppc64el #14321414

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passed meson-x86_64 #14321410

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