scripts: Makefile.spl: Enable memory drivers to be built for SPL

Introduce CONFIG_SPL_MEMORY to allow Memory drivers to
be built for SPL.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index b1b9e09..b738c74 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -796,6 +796,13 @@
 	  this option to build the drivers in drivers/mailbox as part of
 	  SPL build.
 
+config SPL_MEMORY
+	bool "Support Memory controller drivers"
+	help
+	  Enable support for Memory Controller drivers within SPL.
+	  These devices provide Memory bus interface to various devices like
+	  SRAM, Ethernet adapters, FPGAs, etc.
+
 config SPL_MMC
 	bool "Support MMC"
 	depends on MMC
diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl
index 0b3a51d..15ac872 100644
--- a/scripts/Makefile.spl
+++ b/scripts/Makefile.spl
@@ -114,6 +114,7 @@
 endif
 
 libs-y += drivers/
+libs-$(CONFIG_SPL_MEMORY) += drivers/memory/
 libs-$(CONFIG_SPL_USB_GADGET) += drivers/usb/dwc3/
 libs-$(CONFIG_SPL_USB_GADGET) += drivers/usb/cdns3/
 libs-y += dts/