spi: cadence_qspi: get sram size from device tree

sram size could be different on different socs, e.g. on stv0991 it is 256 while
on altera platform it is 128. It is better to receive it from device tree.

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
Tested-by: Stefan Roese <sr@denx.de>
Reviewed-by: Jagannadh Teki <jteki@openedev.com>
diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
index fb78892..cbf0d42 100644
--- a/drivers/spi/cadence_qspi_apb.c
+++ b/drivers/spi/cadence_qspi_apb.c
@@ -36,9 +36,6 @@
 
 #define CQSPI_FIFO_WIDTH			(4)
 
-/* Controller sram size in word */
-#define CQSPI_REG_SRAM_SIZE_WORD		(128)
-#define CQSPI_REG_SRAM_PARTITION_RD		(CQSPI_REG_SRAM_SIZE_WORD/2)
 #define CQSPI_REG_SRAM_THRESHOLD_WORDS		(50)
 
 /* Transfer mode */
@@ -536,8 +533,7 @@
 	writel(0, plat->regbase + CQSPI_REG_REMAP);
 
 	/* Indirect mode configurations */
-	writel(CQSPI_REG_SRAM_PARTITION_RD,
-	       plat->regbase + CQSPI_REG_SRAMPARTITION);
+	writel((plat->sram_size/2), plat->regbase + CQSPI_REG_SRAMPARTITION);
 
 	/* Disable all interrupts */
 	writel(0, plat->regbase + CQSPI_REG_IRQMASK);