random: order timer entropy functions below interrupt functions

commit a4b5c26b79ffdfcfb816c198f2fc2b1e7b5b580f upstream.

There are no code changes here; this is just a reordering of functions,
so that in subsequent commits, the timer entropy functions can call into
the interrupt ones.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>