[Arm-dev] Old dtb directory not deleted

I just did an update that installed a new kernel.  All the old kernel 
files were deleted from /boot except for the dtb directory. In this 
case, dtb-4.14.82-201.el7.armv7hl

Here is a list of the /boot directory.  What is needed to make sure 
everything old is removed from boot?

$ ls -ls /boot/
total 292730
     2 -rw-r--r--. 1 root root        2 Nov  3  2018 boot.scr
   204 -rw-r--r--. 1 root root   206130 Jun 17 20:53 
config-4.14.127-200.el7.armv7hl
   204 -rw-r--r--. 1 root root   206070 Jan  6 09:38 
config-4.14.91-201.el7.armv7hl
    27 drwxr-xr-x. 2 root root    25600 Jun 23 09:19 
dtb-4.14.127-200.el7.armv7hl
    27 drwxr-xr-x. 3 root root    25600 Jun 23 09:23 
dtb-4.14.82-201.el7.armv7hl
    27 drwxr-xr-x. 2 root root    25600 Jan 11 14:44 
dtb-4.14.91-201.el7.armv7hl
     2 drwxr-xr-x. 2 root root     1024 Jun 23 09:29 extlinux
     2 drwxr-xr-x. 2 root root     1024 Dec  5  2016 grub
34835 -rw-------. 1 root root 35529320 Dec  5  2016 
initramfs-0-rescue-e3a7bc0f423e4311a45e7d423cb8743d.img
42323 -rw-------. 1 root root 43166836 Jun 23 09:29 
initramfs-4.14.127-200.el7.armv7hl.img
42243 -rw-------. 1 root root 43085027 Jan 11 14:52 
initramfs-4.14.91-201.el7.armv7hl.img
   597 -rw-r--r--. 1 root root   605252 Dec  5  2016 initrd-plymouth.img
     2 -rw-------. 1 root root       49 Jun 23 09:29 klist.txt
    13 drwx------. 2 root root    12288 Dec  5  2016 lost+found
  3374 -rw-------. 1 root root  3438384 Jun 17 20:53 
System.map-4.14.127-200.el7.armv7hl
  3370 -rw-------. 1 root root  3434223 Jan  6 09:38 
System.map-4.14.91-201.el7.armv7hl
  6537 -rw-r--r--. 1 root root  6664768 Jun 23 09:29 uImage
  6537 -rw-r--r--. 1 root root  6664768 Jun 23 09:29 
uImage-4.14.127-200.el7.armv7hl
  6521 -rw-r--r--. 1 root root  6648384 Jan 11 14:52 
uImage-4.14.91-201.el7.armv7hl
42323 -rw-r--r--. 1 root root 43166900 Jun 23 09:29 uInitrd
42323 -rw-r--r--. 1 root root 43166900 Jun 23 09:29 
uInitrd-4.14.127-200.el7.armv7hl
42243 -rw-r--r--. 1 root root 43085091 Jan 11 14:52 
uInitrd-4.14.91-201.el7.armv7hl
  5936 -rwxr-xr-x. 1 root root  6051744 Dec  5  2016 
vmlinuz-0-rescue-e3a7bc0f423e4311a45e7d423cb8743d
  6537 -rwxr-xr-x. 1 root root  6664704 Jun 17 20:53 
vmlinuz-4.14.127-200.el7.armv7hl
  6521 -rwxr-xr-x. 1 root root  6648320 Jan  6 09:38 
vmlinuz-4.14.91-201.el7.armv7hl