mesa: Add R16G16_R16B16_UNORM and related formats

Including the 10 bit variant X6R10X6G10_X6R10X6B10_UNORM. Only the
RG_RB variants seem to have fourccs, so those are the only ones being
added for now, although they would, obviously, be easy to add).

These are used for Y210, Y212, and Y216 fourccs. In particular Y210
is interesting for panfrost, as it is the fourcc used to indicate a
10 bit single plane 4:2:2 encoded as AFBC (similar to how YUYV is
the canonical AFBC for 10 bit 4:2:0).

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35771>

src/util/format/u_format.yaml

@@ -794,6 +794,19 @@
   channels: [UN8, UN8, UN8, UN8]
   swizzles: [X, Y, Z, 1]
 
+# 16 bit versions
+- name: R16G16_R16B16_422_UNORM
+  layout: subsampled
+  colorspace: RGB
+  block: {width: 2, height: 1, depth: 1}
+  channels: [UN16, UN16, UN16, UN16]
+  swizzles: [X, Y, Z, 1]
+- name: X6R10X6G10_X6R10X6B10_422_UNORM
+  layout: subsampled
+  colorspace: RGB
+  block: {width: 2, height: 1, depth: 1}
+  channels: [UN16, UN16, UN16, UN16]
+  swizzles: [X, Y, Z, 1]
 
 # some special formats not fitting anywhere else
 - name: R11G11B10_FLOAT

src/util/format/u_format_table.py

@@ -110,6 +110,8 @@ def has_access(format):
         'g8r8_g8b8_422_unorm',
         'g8b8_g8r8_422_unorm',
         'b8g8_r8g8_422_unorm',
+        'r16g16_r16b16_422_unorm',
+        'x6r10x6g10_x6r10x6b10_422_unorm',
         'x6g10_x6b10x6r10_420_unorm',
         'x4g12_x4b12x4r12_420_unorm',
         'y8_400_unorm',