i2c: designware: Convert driver to multibus/multiadapter framework

In preparation for the SoCFPGA support of the designware I2C driver,
convert this driver to the common CONFIG_SYS_I2C framework.

This patch converts all users of this driver, this is:

- ST spearxxx boards
- AXS101 (ARC700 platform)

I couldn't test this patch on those boards. Only compile tested for all
spear boards. And tested on SoCFPGA.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Tested-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Vipin Kumar <vk.vipin@gmail.com>
Cc: Jeroen Hofstee <jeroen@myspectrum.nl>