sb/amd: Fix grammar in comment

Change-Id: I478a59534ec997947855eb0ff228a0dd9e15a5a5
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-on: https://review.coreboot.org/29567
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/src/southbridge/amd/cimx/sb800/spi.c b/src/southbridge/amd/cimx/sb800/spi.c
index 54dd77a..ec18454 100644
--- a/src/southbridge/amd/cimx/sb800/spi.c
+++ b/src/southbridge/amd/cimx/sb800/spi.c
@@ -57,7 +57,7 @@
 static int spi_ctrlr_xfer(const struct spi_slave *slave, const void *dout,
 		size_t bytesout, void *din, size_t bytesin)
 {
-	/* First byte is cmd which can not being sent through FIFO. */
+	/* First byte is cmd which can not be sent through FIFO. */
 	u8 cmd = *(u8 *)dout++;
 	u8 readoffby1;
 	u8 readwrite;