linux/types.h: enable endian checks for all sparse builds

linux/types.h: enable endian checks for all sparse builds

By now, linux is mostly endian-clean. Enabling endian-ness
checks for everyone produces about 200 new sparse warnings for me -
less than 10% over the 2000 sparse warnings already there.

Not a big deal, OTOH enabling this helps people notice
they are introducing new bugs.

So let's just drop __CHECK_ENDIAN__. Follow-up patches
can drop distinction between __bitwise and __bitwise__.

Cc: Linus Torvalds <[email protected]>
Suggested-by: Christoph Hellwig <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>