Currently the virtual port_dev device is passed to DMA API, and this is
wrong because the device passed to DMA API calls must be the actual
hardware device performing the DMA.

The patch replaces usb_gadget_map_request/usb_gadget_unmap_request APIs
with usb_gadget_map_request_by_dev/usb_gadget_unmap_request_by_dev APIs
so the DMA capable platform device can be passed to the DMA APIs.

The patch fixes below backtrace detected on Facebook AST2500 OpenBMC
platforms:

[<80106550>] show_stack+0x20/0x24
[<80106868>] dump_stack+0x28/0x30
[<80823540>] __warn+0xfc/0x110
[<8011ac30>] warn_slowpath_fmt+0xb0/0xc0
[<8011ad44>] dma_map_page_attrs+0x24c/0x314
[<8016a27c>] usb_gadget_map_request_by_dev+0x100/0x1e4
[<805cedd8>] usb_gadget_map_request+0x1c/0x20
[<805cefbc>] ast_vhub_epn_queue+0xa0/0x1d8
[<7f02f710>] usb_ep_queue+0x48/0xc4
[<805cd3e8>] ecm_do_notify+0xf8/0x248
[<7f145920>] ecm_set_alt+0xc8/0x1d0
[<7f145c34>] composite_setup+0x680/0x1d30
[<7f00deb8>] ast_vhub_ep0_handle_setup+0xa4/0x1bc
[<7f02ee94>] ast_vhub_dev_irq+0x58/0x84
[<7f0309e0>] ast_vhub_irq+0xb0/0x1c8
[<7f02e118>] __handle_irq_event_percpu+0x50/0x19c
[<8015e5bc>] handle_irq_event_percpu+0x38/0x8c
[<8015e758>] handle_irq_event+0x38/0x4c

Fixes: 7ecca2a4 ("usb/gadget: Add driver for Aspeed SoC virtual hub")
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Tao Ren <rentao.bupt@gmail.com>
Link: https://lore.kernel.org/r/20210331045831.28700-1-rentao.bupt@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>