PCI: dwc: ep: Return -ENOMEM for allocation failures

PCI: dwc: ep: Return -ENOMEM for allocation failures

If the bitmap or memory allocations fail, then dw_pcie_ep_init_registers()
will incorrectly return a success.

Return -ENOMEM instead.

Fixes: 869bc5253406 ("PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/36dcb6fc-f292-4dd5-bd45-a8c6f9dc3df7@stanley.mountain