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/ls1046ardb_emmc_defconfig b/configs/ls1046ardb_emmc_defconfig
index fe06a2e..a319bf3 100644
--- a/configs/ls1046ardb_emmc_defconfig
+++ b/configs/ls1046ardb_emmc_defconfig
@@ -85,7 +85,7 @@
 CONFIG_E1000=y
 CONFIG_FMAN_ENET=y
 CONFIG_SYS_FMAN_FW_ADDR=0x900000
-CONFIG_NVME=y
+CONFIG_NVME_PCI=y
 CONFIG_PCI=y
 CONFIG_PCIE_LAYERSCAPE_RC=y
 CONFIG_PCIE_LAYERSCAPE_EP=y