i2c: mlxbf: Remove unecessary wrapper functions

Few wrapper functions are useless and can be inlined. So
delete mlxbf_i2c_read() and mlxbf_i2c_write() and replace
them with readl() and writel(), respectively. Also delete
mlxbf_i2c_read_data() and mlxbf_i2c_write() and replace
them with ioread32be() and iowrite32be(), respectively.

Fixes: b5b5b320 ("i2c: mlxbf: I2C SMBus driver for Mellanox BlueField SoC")
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Signed-off-by: Khalil Blaiech <kblaiech@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>