agx: Rename "combine" to "collect"

For consistency with ir3 and bifrost.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18804>

src/asahi/compiler/agx_opcodes.py

@@ -265,7 +265,7 @@ op("or", _, srcs = 2)
 # Indicates the logical end of the block, before final branches/control flow
 op("logical_end", _, dests = 0, srcs = 0, can_eliminate = False)
 
-op("combine", _, srcs = VARIABLE)
+op("collect", _, srcs = VARIABLE)
 op("split", _, srcs = 1, dests = VARIABLE)
 op("phi", _, srcs = VARIABLE)