Convert CONFIG_SCSI_AHCI_PLAT et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SCSI_AHCI_PLAT
   CONFIG_SYS_SCSI_MAX_SCSI_ID
   CONFIG_SYS_SCSI_MAX_LUN
   CONFIG_SYS_SATA_MAX_DEVICE

Drop CONFIG_SCSI for everything except the sandbox build. We only need
one build for tests.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index faa991d..3ca1f56 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -128,6 +128,7 @@
 CONFIG_SIMPLE_PM_BUS=y
 CONFIG_ADC=y
 CONFIG_ADC_SANDBOX=y
+CONFIG_SYS_SATA_MAX_DEVICE=2
 CONFIG_AXI=y
 CONFIG_AXI_SANDBOX=y
 CONFIG_SYS_IDE_MAXBUS=1
@@ -256,6 +257,9 @@
 CONFIG_DM_RNG=y
 CONFIG_DM_RTC=y
 CONFIG_RTC_RV8803=y
+CONFIG_SCSI_AHCI_PLAT=y
+CONFIG_SYS_SCSI_MAX_SCSI_ID=8
+CONFIG_SYS_SCSI_MAX_LUN=4
 CONFIG_SANDBOX_SERIAL=y
 CONFIG_SMEM=y
 CONFIG_SANDBOX_SMEM=y
@@ -265,6 +269,7 @@
 CONFIG_SOUND_SANDBOX=y
 CONFIG_SOC_DEVICE=y
 CONFIG_SANDBOX_SPI=y
+CONFIG_SCSI=y
 CONFIG_SPMI=y
 CONFIG_SPMI_SANDBOX=y
 CONFIG_SYSINFO=y