Fixes dEQP-EGL.functional.wide_color#window_888_colorspace_srgb on ARCVM, which uses a 24 bit-per-pixel R8G8B8_UNORM surface format that slipped through the cracks during the latest BGRA rework in !725 (merged).
Fixes: 187e6513 ("vrend: avoid srgb views on eglimage-backed surfaces")
This also clarifies the special cases a bit better by adding a new helper
bool vrend_resource_needs_redblue_swizzle(res, view_format);.
I'm running the full dEQP suite on ARCVM now; will notify here when it finishes.