nvme: Split out PCI support

Apple SoCs have an integrated NVMe controller that isn't connected
over a PCIe bus. In preparation for adding support for this NVMe
controller, split out the PCI support into its own file. This file
is selected through a new CONFIG_NVME_PCI Kconfig option, so do
a wholesale replacement of CONFIG_NVME with CONFIG_NVME_PCI.

Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested on: Macbook Air M1
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox64_defconfig b/configs/sandbox64_defconfig
index d82c180..7c157a2 100644
--- a/configs/sandbox64_defconfig
+++ b/configs/sandbox64_defconfig
@@ -167,7 +167,7 @@
 CONFIG_SPI_FLASH_SST=y
 CONFIG_SPI_FLASH_WINBOND=y
 CONFIG_DM_ETH=y
-CONFIG_NVME=y
+CONFIG_NVME_PCI=y
 CONFIG_PCI=y
 CONFIG_PCI_SANDBOX=y
 CONFIG_PHY=y