Add MMCCAM-enabled kernel config for IMX6, reduce debug noice in MMCCAM kernels

CAM_DEBUG_TRACE results in way too much debug output than needed now.
When debugging, it's always possible to turn on trace level using camcontrol.

Approved by:	imp (mentor)
Differential Revision:	https://reviews.freebsd.org/D12110

sys/amd64/conf/GENERIC-MMCCAM

@@ -4,7 +4,7 @@
 
 include         MINIMAL
 
-ident		MMCCAM
+ident		GENERIC-MMCCAM
 
 # Access GPT-formatted and labeled root volume
 options         GEOM_PART_GPT
@@ -28,9 +28,9 @@ device		virtio_balloon		# VirtIO Memory Balloon device
 device		pass
 device		scbus
 device		da
-device		mmccam
 
-options	MMCCAM
+options	       MMCCAM
+
 # Add CAMDEBUG stuff
-options CAMDEBUG
-options CAM_DEBUG_FLAGS=(CAM_DEBUG_INFO|CAM_DEBUG_PROBE|CAM_DEBUG_PERIPH|CAM_DEBUG_TRACE)
+options	       CAMDEBUG
+options	       CAM_DEBUG_FLAGS=(CAM_DEBUG_INFO|CAM_DEBUG_PROBE|CAM_DEBUG_PERIPH)

sys/arm/conf/BEAGLEBONE-MMCCAM

@@ -6,16 +6,18 @@
 #
 # $FreeBSD$
 
+#NO_UNIVERSE
+
 include		BEAGLEBONE
 
+options		MMCCAM
+
 # Add CAMDEBUG stuff
 options 	CAMDEBUG
-options 	CAM_DEBUG_FLAGS=(CAM_DEBUG_INFO|CAM_DEBUG_PROBE|CAM_DEBUG_PERIPH|CAM_DEBUG_TRACE)
+options 	CAM_DEBUG_FLAGS=(CAM_DEBUG_INFO|CAM_DEBUG_PROBE|CAM_DEBUG_PERIPH)
 
 # pass(4) device
 device		pass
-device		mmccam
-options		MMCCAM
 
 nodevice	mmc
 nodevice	mmcsd

sys/arm/conf/IMX6-MMCCAM

@@ -0,0 +1,23 @@
+#
+# IMX6-MMCCAM
+#
+# Custom kernel for IMX6 plus MMCCAM as opposed to the prior MMC stack. It is
+# present to keep it building in tree since it wouldn't work in LINT.
+#
+# $FreeBSD$
+
+#NO_UNIVERSE
+
+include		IMX6
+
+options		MMCCAM
+
+# Add CAMDEBUG stuff
+options 	CAMDEBUG
+options 	CAM_DEBUG_FLAGS=(CAM_DEBUG_INFO|CAM_DEBUG_PROBE|CAM_DEBUG_PERIPH)
+
+# pass(4) device
+device		pass
+
+nodevice	mmc
+nodevice	mmcsd