Update SRAM.scala to improve perf on non-full sized reads

Change a_sublane to not count sublanes if it's a read. Reads return full data width, no matter if the A channel size is not the data width

src/main/scala/tilelink/SRAM.scala

@@ -229,14 +229,15 @@ class TLRAM(
     val r_ready = !d_wb && !r_replay && (!d_full || d_ready) && (!r_respond || (!d_win && in.d.ready))
     in.a.ready := !(d_full && d_wb) && (!r_full || r_ready) && (!r_full || !(r_atomic || r_sublane))
 
-    // ignore sublane if mask is all set
+    // ignore sublane if it is a read or mask is all set
+    val a_read = in.a.bits.opcode === TLMessages.Get
     val a_sublane = if (eccBytes == 1) false.B else
-      ((in.a.bits.opcode === TLMessages.PutPartialData) && (~in.a.bits.mask.andR)) ||
-      in.a.bits.size < log2Ceil(eccBytes).U
+      ~a_read && 
+      (((in.a.bits.opcode === TLMessages.PutPartialData) && (~in.a.bits.mask.andR)) ||
+      in.a.bits.size < log2Ceil(eccBytes).U)
     val a_atomic = if (!atomics) false.B else
       in.a.bits.opcode === TLMessages.ArithmeticData ||
       in.a.bits.opcode === TLMessages.LogicalData
-    val a_read = in.a.bits.opcode === TLMessages.Get
 
     // Forward pipeline stage from R to D
     when (d_ready) { d_full := false.B }