Fix some typos found by codespell

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

target-mips/op_helper.c

@@ -581,7 +581,7 @@ static bool mips_vp_is_wfi(MIPSCPU *c)
 
 static inline void mips_vpe_wake(MIPSCPU *c)
 {
-    /* Dont set ->halted = 0 directly, let it be done via cpu_has_work
+    /* Don't set ->halted = 0 directly, let it be done via cpu_has_work
        because there might be other conditions that state that c should
        be sleeping.  */
     cpu_interrupt(CPU(c), CPU_INTERRUPT_WAKE);