Structure ufs_dev_params is actually used in UFS host vendor drivers to
declare host specific power mode parameters, like ufs_<vendor>_params or
host_cap, which makes the code not very straightforward to read. Rename the
structure ufs_dev_params to ufs_host_params and unify the declarations in
all vendor drivers to host_params.
In addition, rename the two functions ufshcd_init_pwr_dev_param() and
ufshcd_get_pwr_dev_param() which work based on the ufs_host_params to
ufshcd_init_host_params() and ufshcd_negotiate_pwr_params() respectively to
avoid confusions.
This change does not change any functionalities or logic.