spi: Allow separate control of SPI_FLASH_TINY for SPL/TPL

In some cases SPL needs to be able to erase but TPL just needs to read.
Allow these to have separate settings for SPI_FLASH_TINY.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/mtd/spi/Makefile b/drivers/mtd/spi/Makefile
index 952fd1e..99cc418 100644
--- a/drivers/mtd/spi/Makefile
+++ b/drivers/mtd/spi/Makefile
@@ -8,7 +8,7 @@
 
 ifdef CONFIG_SPL_BUILD
 obj-$(CONFIG_SPL_SPI_BOOT)	+= fsl_espi_spl.o
-ifeq ($(CONFIG_SPL_SPI_FLASH_TINY),y)
+ifeq ($(CONFIG_$(SPL_TPL_)SPI_FLASH_TINY),y)
 spi-nor-y += spi-nor-tiny.o
 else
 spi-nor-y += spi-nor-core.o