i2c: rcar: refactor status bit handling

i2c: rcar: refactor status bit handling

The old macros made it harder to see what was actually happening.
Replace them with something more readable.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
(cherry picked from commit 3c95de674496e08d3b373f85af4aa59c23ddb8d6)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>