fix(pio): broken bitReverse function (#87)

pretty self-explanatory, this is another bug I found while playing around with the PIOs.

https://jsfiddle.net/bwn6j75r/

Cheers!

Author: martin2250

src/peripherals/pio.ts

@@ -81,11 +81,11 @@ export enum WaitType {
 }
 
 function bitReverse(x: number) {
-  x = ((x & 0x55555555) << 1) | ((x & 0xaaaaaaaa) >> 1);
-  x = ((x & 0x33333333) << 2) | ((x & 0xcccccccc) >> 2);
-  x = ((x & 0x0f0f0f0f) << 4) | ((x & 0xf0f0f0f0) >> 4);
-  x = ((x & 0x00ff00ff) << 8) | ((x & 0xff00ff00) >> 8);
-  x = ((x & 0x0000ffff) << 16) | ((x & 0xffff0000) >> 16);
+  x = ((x & 0x55555555) << 1) | ((x & 0xaaaaaaaa) >>> 1);
+  x = ((x & 0x33333333) << 2) | ((x & 0xcccccccc) >>> 2);
+  x = ((x & 0x0f0f0f0f) << 4) | ((x & 0xf0f0f0f0) >>> 4);
+  x = ((x & 0x00ff00ff) << 8) | ((x & 0xff00ff00) >>> 8);
+  x = ((x & 0x0000ffff) << 16) | ((x & 0xffff0000) >>> 16);
   return x >>> 0;
 }