color_space_helper: Allow all texture formats for the sRGB color space

Most texture formats should be presentable on the default sRGB color
space, in particular 10-bit formats for higher bit depth and detail than
the typical 8-bit.

A couple notes:
- This currently only affects `VK_KHR_display` as there is a
  `needsWorkaround` case in `PhysicalDevice::GetSurfaceFormats()` that
  returns exclusively RGBA8 and BGRA8 in the windowed/compositor case;
- Before this patch, `A2B10G10R10` wasn't in the list returned by
  `vkGetPhysicalDeviceSurfaceFormatsKHR()` but worked anyway on
  `VK_KHR_display` _without_ validation errors;
- Using the `A2B10G10R10` format inside a 10-bit compositor works
  anyway, albeit with validation layer errors;
- RADV also allows 10-bit sRGB swapchains, but only in a compositor, not
  in `VK_KHR_display`;
- Windows also does not report support for this 10-bit sRGB format
  combination, but it works anyway (also with validation layer errors);
- By using `Fmt_All`, the `R16G16B16A16_UNORM` and `R16G16B16A16_SFLOAT`
  formats become available for the sRGB color space, but creating
  a swapchain with them leaves a black screen.  If this is truly
  unsupported, perhaps there should be a new `Fmt_8bpc_10bpc`?
- This was previously `Fmt_All` already before commit 02e867e ("Update
  xgl from commit 2aeb0b25") but it is assumed that sub-commit "Fix
  ColorspaceHelper's lookup table so it only reports formats that are
  legal" changed this behaviour. At least 10-bit sRGB should be retained?

(When saying "it works", I mean that it works as intended, i.e.
any 8-bit banding previously observable is gone when using a 10-bit
swapchain)

icd/api/color_space_helper.cpp

@@ -51,7 +51,7 @@ struct LookupDefines
 
 const LookupDefines colorspaceLookup[] =
 {
-    { Pal::ScreenColorSpace::CsSrgb,         VK_COLOR_SPACE_SRGB_NONLINEAR_KHR,       FmtSupport::Fmt_8bpc         },
+    { Pal::ScreenColorSpace::CsSrgb,         VK_COLOR_SPACE_SRGB_NONLINEAR_KHR,       FmtSupport::Fmt_All          },
     { Pal::ScreenColorSpace::CsBt709,        VK_COLOR_SPACE_BT709_NONLINEAR_EXT,      FmtSupport::Fmt_All          },
     { Pal::ScreenColorSpace::TfHlg,          VK_COLOR_SPACE_HDR10_HLG_EXT,            FmtSupport::Fmt_KnownHDR     },
     { Pal::ScreenColorSpace::TfPq2084,       VK_COLOR_SPACE_HDR10_ST2084_EXT,         FmtSupport::Fmt_10bpc        },