spl: dm: Kconfig: introduce TPL_RAM (in analogy to SPL_RAM)

To allow finer grained selection of features for TPL, we introduce
TPL_RAM (in analogy to SPL_RAM).

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>

drivers/ram/Kconfig

@@ -17,6 +17,15 @@ config SPL_RAM
 	  SPL, enable this option. It might provide a cleaner interface to
 	  setting up RAM (e.g. SDRAM / DDR) within SPL.
 
+config TPL_RAM
+	bool "Enable RAM support in SPL"
+	depends on RAM && TPL_DM
+	help
+	  The RAM subsystem adds a small amount of overhead to the image.
+	  If this is acceptable and you have a need to use RAM drivers in
+	  TPL, enable this option. It might provide a cleaner interface to
+	  setting up RAM (e.g. SDRAM / DDR) within TPL.
+
 config STM32_SDRAM
 	bool "Enable STM32 SDRAM support"
 	depends on RAM