R600/SI: Remove useless patterns in VALU which are already covered by SALU
R600/SI: Remove useless patterns in VALU which are already covered by SALU

Also remove hasPostISelHook=1 from V_LSHL_B32. It's defined by InstSI already.

Tested-by: Michel Dänzer <michel.daenzer@amd.com>

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@228039 91177308-0d34-0410-b5e6-96231b3b80d8

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