ARM: imx8m: verdin-imx8mm: Increase bootm size to 64 MiB

Uncompressed aarch64 kernel Image are rather large, increase the bootm
size limit to 64 MiB to cater for that.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Cc: Max Krummenacher <max.krummenacher@toradex.com>
Cc: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
diff --git a/include/configs/verdin-imx8mm.h b/include/configs/verdin-imx8mm.h
index e2a8178..7be5e5d 100644
--- a/include/configs/verdin-imx8mm.h
+++ b/include/configs/verdin-imx8mm.h
@@ -16,6 +16,8 @@
 #define CONFIG_SYS_UBOOT_BASE	\
 	(QSPI0_AMBA_BASE + CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR * 512)
 
+#define CONFIG_SYS_BOOTM_LEN           SZ_64M
+
 #ifdef CONFIG_SPL_BUILD
 #define CONFIG_SPL_STACK		0x920000
 #define CONFIG_SPL_BSS_START_ADDR	0x910000