i2c: mv_i2c.c: cosmetic: Coding style cleanups

Some mostly indentation coding style cleanups. Also, move this driver
to use debug() for debug output.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Nadav Haklai <nadavh@marvell.com>
Cc: Kostya Porotchkin <kostap@marvell.com>
Cc: Wilson Ding <dingwei@marvell.com>
Cc: Victor Gu <xigu@marvell.com>
Cc: Hua Jing <jinghua@marvell.com>
Cc: Terry Zhou <bjzhou@marvell.com>
Cc: Hanna Hawa <hannah@marvell.com>
Cc: Haim Boot <hayim@marvell.com>
Cc: Heiko Schocher <hs@denx.de>