ARM: bcm2835_defconfig: Explicitly restore CONFIG_DEBUG_FS

The commit 0e4a459f ("tracing: Remove unnecessary DEBUG_FS dependency")
accidentally dropped the DEBUG FS support in bcm2835_defconfig. So
restore the config as before the commit.
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: 0e4a459f ("tracing: Remove unnecessary DEBUG_FS dependency")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm/configs/bcm2835_defconfig

@@ -178,6 +178,7 @@ CONFIG_SCHED_TRACER=y
 CONFIG_STACK_TRACER=y
 CONFIG_FUNCTION_PROFILER=y
 CONFIG_TEST_KSTRTOX=y
+CONFIG_DEBUG_FS=y
 CONFIG_KGDB=y
 CONFIG_KGDB_KDB=y
 CONFIG_STRICT_DEVMEM=y