Always use workaround for blitting to/from BC6H

Always use workaround for blitting to/from BC6H

Qualcomm's implementation of cubic filtering can give large inaccuracies
when texel values within the 4x4 grid are very big and very small,
especially if the values around the "edge" are much bigger then the
values at the center. This can happen with randomly-generated blocks for
floating-point compressed formats like BC6H. There was already a
workaround for similar issues seen blitting to e5b9g9r9, extend it to
all formats to fix this.

Components: Vulkan

VK-GL-CTS Issue: 3450

Affects:
dEQP-VK.api.copy_and_blit.core.blit_image.all_formats.color.2d.bc6h_ufloat_block.*
dEQP-VK.api.copy_and_blit.core.blit_image.all_formats.color.2d.*.bc6h_ufloat_block.*

Change-Id: I3445ecba2ebc9e4e52e26111a109eaf79f611bd8