x86: add NVMe support for motherboards w/ M.2 slot

A lot of 1U x86_64 servers have NVMe support, which is lower-power
and higher speed than SSD or CFast drives, etc.  The drivers
required to make this work are trivial.

Signed-off-by: Philip Prindeville <[email protected]>

target/linux/x86/config-4.9

@@ -49,6 +49,8 @@ CONFIG_ATA_GENERIC=y
 CONFIG_ATA_PIIX=y
 CONFIG_BINFMT_MISC=y
 CONFIG_BLK_DEV_LOOP=y
+CONFIG_BLK_DEV_NVME=y
+# CONFIG_BLK_DEV_NVME_SCSI is not set
 CONFIG_BLK_DEV_SD=y
 CONFIG_BLK_MQ_PCI=y
 CONFIG_BOUNCE=y
@@ -322,6 +324,7 @@ CONFIG_NLS=y
 CONFIG_NO_BOOTMEM=y
 CONFIG_NR_CPUS=1
 # CONFIG_NSC_GPIO is not set
+CONFIG_NVME_CORE=y
 CONFIG_NVRAM=y
 # CONFIG_OF is not set
 CONFIG_OLD_SIGACTION=y