sdcard: Set stop bit in SPI command frame.

fix in upstream repo:
micropython/micropython-lib#1079

Author: c0ffee2code

telemetry/sdcard.py

@@ -155,7 +155,7 @@ def cmd(self, cmd, arg, crc, final=0, release=True, skip1=False):
         buf[2] = arg >> 16
         buf[3] = arg >> 8
         buf[4] = arg
-        buf[5] = crc
+        buf[5] = crc | 0x01  # ensure stop bit is always set
         self.spi.write(buf)
 
         if skip1: