drivers: staging: most: use swabXX functions of kernel

This patch makes use of the swab16() and swab32() functions available
in the kernel instead of using own implementations.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/1604494242-3414-1-git-send-email-christian.gromm@microchip.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>