sha/asm/keccak1600-armv4.pl: improve non-NEON performance by ~10%.

This is achieved mostly by ~10% reduction of amount of instructions
per round thanks to a) switch to KECCAK_2X variant; b) merge of
almost 1/2 rotations with logical instructions. Performance is
improved on all observed processors except on Cortex-A15. This is
because it's capable of exploiting more parallelism and can execute
original code for same amount of time.

Reviewed-by: Rich Salz <[email protected]>
Reviewed-by: Bernd Edlinger <[email protected]>
(Merged from openssl#4057)