um: fix ndelay/udelay defines

Many places in the kernel use 'udelay' as an identifier, and
are broken with the current "#define udelay um_udelay". Fix
this by adding an argument to the macro, and do the same to
'ndelay' as well, just in case.

Fixes: 0bc8fb4d

 ("um: Implement ndelay/udelay in time-travel mode")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>