drivers: i3c: shell: fix unhandled `<id>` argument parsing

The `<id>` argument was included in `cmd_i3c_ccc_getvendor`,
`cmd_i3c_ccc_setvendor`, and `cmd_i3c_ccc_setvendor_bc` but
was not processed.

Utilized `shell_strtoul` for proper parsing of the `<id>` argument
in these functions.

Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>