Add encodings for Zvqdotq instrutions (#337)

Author: aswaterman

extensions/unratified/rv_zvqdotq

@@ -0,0 +1,7 @@
+vqdot.vv         31..26=0x2c vm vs2 vs1 14..12=0x2 vd 6..0=0x57
+vqdot.vx         31..26=0x2c vm vs2 rs1 14..12=0x6 vd 6..0=0x57
+vqdotu.vv        31..26=0x28 vm vs2 vs1 14..12=0x2 vd 6..0=0x57
+vqdotu.vx        31..26=0x28 vm vs2 rs1 14..12=0x6 vd 6..0=0x57
+vqdotsu.vv       31..26=0x2a vm vs2 vs1 14..12=0x2 vd 6..0=0x57
+vqdotsu.vx       31..26=0x2a vm vs2 rs1 14..12=0x6 vd 6..0=0x57
+vqdotus.vx       31..26=0x2e vm vs2 rs1 14..12=0x6 vd 6..0=0x57