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/P2041RDB_SDCARD_defconfig b/configs/P2041RDB_SDCARD_defconfig
index 997f461..dc56c79 100644
--- a/configs/P2041RDB_SDCARD_defconfig
+++ b/configs/P2041RDB_SDCARD_defconfig
@@ -41,6 +41,7 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_DM=y
+CONFIG_SYS_SATA_MAX_DEVICE=2
 CONFIG_FSL_CAAM=y
 CONFIG_SYS_BR0_PRELIM_BOOL=y
 CONFIG_SYS_BR0_PRELIM=0xE8001001