Documentation: update .gitignore files

Add some missing files to .gitignore.
Push Documentation/.gitignore down into subdirectories.

Signed-off-by: Peter Foley <pefoley2@pefoley.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Documentation/.gitignore

@@ -1,7 +0,0 @@
-filesystems/dnotify_test
-laptops/dslm
-timers/hpet_example
-vm/hugepage-mmap
-vm/hugepage-shm
-vm/map_hugetlb
-

Documentation/arm/SH-Mobile/.gitignore

@@ -0,0 +1 @@
+vrl4

Documentation/filesystems/.gitignore

@@ -0,0 +1 @@
+dnotify_test

Documentation/laptops/.gitignore

@@ -0,0 +1,2 @@
+dslm
+freefall

Documentation/networking/timestamping/.gitignore

@@ -1,2 +1,3 @@
 timestamping
+txtimestamp
 hwtstamp_config

Documentation/prctl/.gitignore

@@ -0,0 +1,3 @@
+disable-tsc-ctxt-sw-stress-test
+disable-tsc-on-off-stress-test
+disable-tsc-test

Documentation/ptp/.gitignore

@@ -0,0 +1 @@
+testptp

Documentation/timers/.gitignore

@@ -0,0 +1 @@
+hpet_example

Documentation/vDSO/.gitignore

@@ -0,0 +1,2 @@
+vdso_test
+vdso_standalone_test_x86

Documentation/video4linux/.gitignore

@@ -1 +0,0 @@
-v4lgrab