crypto: arc4 - improve performance by adding ecb(arc4)

Currently arc4.c provides simple one-byte blocksize cipher which is wrapped
by ecb() module, giving function call overhead on every encrypted byte. This
patch adds ecb(arc4) directly into arc4.c for higher performance.

tcrypt results (speed ratios: new/old):

AMD Phenom II, x86-64 : x2.7
Intel Core 2, x86-64  : x1.9
Intel Atom N260, i386 : x1.4

Change-Id: Iaf331982b67f2ffd67adc10508a55d1c673d3467
Cc: Jon Oberheide <jon@oberheide.org>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: zwliew <zhaoweiliew@gmail.com>
crypto: arc4 - improve performance by using u32 for ctx and variables

This patch changes u8 in struct arc4_ctx and variables to u32 (as AMD seems
to have problem with u8 array). Below are tcrypt results of old 1-byte block
cipher versus ecb(arc4) with u8 and ecb(arc4) with u32.

tcrypt results, x86-64 (speed ratios: new-u32/old, new-u8/old):

                  u32    u8
AMD Phenom II   : x3.6   x2.7
Intel Core 2    : x2.0   x1.9

tcrypt results, i386 (speed ratios: new-u32/old, new-u8/old):

                  u32    u8
Intel Atom N260 : x1.5   x1.4

Change-Id: I8619ac9a9298b5af185628c4b5903c1f62b637df
Cc: Jon Oberheide <jon@oberheide.org>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: zwliew <zhaoweiliew@gmail.com>