video: Rename CONFIG_SYS_VIDEO_LOGO_MAX_SIZE

This option should not have the SYS_ in it. Drop it so it fits in with the
other video options.

Also simplify the alignment code in gunzip_bmp(), since malloc() always
returns a 32-bit-aligned pointer.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 3e933ed..d160271 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -925,6 +925,9 @@
 	  images, gzipped BMP images can be displayed via the
 	  splashscreen support or the bmp command.
 
+config VIDEO_LOGO_MAX_SIZE
+	bool "Maximum size of the bitmap logo in bytes"
+
 config VIDEO_BMP_RLE8
 	bool "Run length encoded BMP image (RLE8) support"
 	depends on DM_VIDEO