MXSCM-213: remove dmfc from boot arguments for mx6scm boards

Intially this parameter was added to fix a video stuttering but
with L4.1 the video issue is not present so we can safely get rid
of this parameter.

When using both ldb interfaces in separate mode and passing the
dmfc argument as boot parameter to the kernel, a distortion on
both displays is observed when rendering to the secondary display.

Signed-off-by: Juan Gutierrez <juan.gutierrez@nxp.com>

include/configs/mx6dqscm.h

@@ -61,7 +61,6 @@
 #define CONFIG_CONSOLE_DEV      "ttymxc0"
 #endif
 #define CONFIG_MMCROOT          "/dev/mmcblk2p2"  /* SDHC3 */
-#define CONFIG_DMFC             "dmfc=3"
 
 #define CONFIG_SYS_MMC_IMG_LOAD_PART    1
 
@@ -346,7 +345,6 @@
 	"mmcdev=" __stringify(CONFIG_SYS_MMC_ENV_DEV) "\0" \
 	"mmcpart=" __stringify(CONFIG_SYS_MMC_IMG_LOAD_PART) "\0" \
 	"mmcroot=" CONFIG_MMCROOT " rootwait rw\0" \
-	"dmfc=" CONFIG_DMFC "\0" \
 	"mmcautodetect=yes\0" \
 	"update_sd_firmware=" \
 		"if test ${ip_dyn} = yes; then " \
@@ -364,7 +362,7 @@
 	EMMC_ENV	  \
 	"smp=" CONFIG_SYS_NOSMP "\0"\
 	"mmcargs=setenv bootargs console=${console},${baudrate} ${smp} " \
-		"root=${mmcroot} ${dmfc}\0" \
+		"root=${mmcroot} \0" \
 	"loadbootscript=" \
 		"fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};\0" \
 	"bootscript=echo Running bootscript from mmc ...; " \
@@ -464,7 +462,6 @@
 	"mmcdev=" __stringify(CONFIG_SYS_MMC_ENV_DEV) "\0" \
 	"mmcpart=" __stringify(CONFIG_SYS_MMC_IMG_LOAD_PART) "\0" \
 	"mmcroot=" CONFIG_MMCROOT " rootwait rw\0" \
-	"dmfc=" CONFIG_DMFC "\0" \
 	"mmcautodetect=yes\0" \
 	"update_sd_firmware=" \
 		"if test ${ip_dyn} = yes; then " \
@@ -482,7 +479,7 @@
 	EMMC_ENV	  \
 	"smp=" CONFIG_SYS_NOSMP "\0"\
 	"mmcargs=setenv bootargs console=${console},${baudrate} ${smp} " \
-		"root=${mmcroot} ${dmfc} \0" \
+		"root=${mmcroot} \0" \
 	"loadbootscript=" \
 		"fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};\0" \
 	"bootscript=echo Running bootscript from mmc ...; " \