arch-riscv: Remove warning message in senvcfg setMiscReg

Previously, a warning would be printed when the WPRI bits
in the senvcfg register were written to. The other registers
do not print warnings for this, so the warning is being
removed.

src/arch/riscv/isa.cc

@@ -797,12 +797,7 @@ ISA::setMiscReg(RegIndex idx, RegVal val)
                     val);
                 }
 
-                if ((wpri_mask & val) != 0) {
-                    warn("Ignoring write to WPRI bit(s) in senvcfg CSR.\n"
-                    "The attempted write was:\n %" PRIu64 "\n", val);
-                } else {
-                    setMiscRegNoEffect(idx, val);
-                }
+                setMiscRegNoEffect(idx, val & ~wpri_mask);
             }
             break;
           case MISCREG_TSELECT: