bios: litespi: clear rx queue after write

clear rx queue at the end of spiflash_master_write().

Signed-off-by: Fin Maaß <f.maass@vogl-electronic.com>

litex/soc/software/liblitespi/spiflash.c

@@ -111,6 +111,9 @@ static void spiflash_master_write(uint32_t val, size_t len, size_t width, uint32
 	spiflash_core_master_rxtx_write(val);
 	while (!spiflash_rx_ready());
 
+	/* Clear RX queue. */
+	spiflash_core_master_rxtx_read();
+
 	/* Clear CS. */
 	spiflash_core_master_cs_write(0);
 }

litex/soc/software/liblitespi/spiram.c

@@ -97,6 +97,9 @@ static void spiram_master_write(uint32_t val, size_t len, size_t width, uint32_t
 	spiram_core_master_rxtx_write(val);
 	while (!spiram_rx_ready());
 
+	/* Clear RX queue. */
+	spiflash_core_master_rxtx_read();
+
 	/* Clear CS. */
 	spiram_core_master_cs_write(0);
 }