PCI: endpoint: Make PCI_ENDPOINT depend on HAS_DMA
If NO_DMA=y:
drivers/built-in.o: In function `__pci_epc_create':
(.text+0xef4e): undefined reference to `bad_dma_ops'
drivers/built-in.o: In function `pci_epc_add_epf':
(.text+0xf676): undefined reference to `bad_dma_ops'
drivers/built-in.o: In function `pci_epf_alloc_space':
(.text+0xfa32): undefined reference to `bad_dma_ops'
drivers/built-in.o: In function `pci_epf_free_space':
(.text+0xfac4): undefined reference to `bad_dma_ops'