configs: bx50v3: Fix boot hang with video

Fixes commit: 0b09f7b15052bb419e318e38da453be46e5a13e5, which converted
to DM_VIDEO, but requires more memory.

[Inspired by 9002e735e71754a90adbb9676c0ffb1964dbc288]

Signed-off-by: Ian Ray <ian.ray@ge.com>
Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
diff --git a/configs/ge_bx50v3_defconfig b/configs/ge_bx50v3_defconfig
index d735089..f5f471e 100644
--- a/configs/ge_bx50v3_defconfig
+++ b/configs/ge_bx50v3_defconfig
@@ -73,3 +73,4 @@
 CONFIG_WATCHDOG_TIMEOUT_MSECS=6000
 CONFIG_IMX_WATCHDOG=y
 # CONFIG_EFI_LOADER is not set
+CONFIG_SYS_MALLOC_F_LEN=0x4000