rtc: max77686: Use ffs() to calculate tm_wday
rtc: max77686: Use ffs() to calculate tm_wday

max77686_rtc_calculate_wday() is used to calculate the day of the week
to be filled in struct rtc_time but that function only calculates the
number of bits shifted.  So the ffs() function can be used to find the
first bit set instead of a special function.

[5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org: add comment clarifying ffs() use]
Signed-off-by: Javier Martinez Canillas <039000e09e601bba70626bd0fbe59654c9cf8cac@collabora.co.uk>
Cc: Joe Perches <16a9a54ddf4259952e3c118c763138e83693d7fd@perches.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs