drm/atmel-hlcdc: fix memory leak from the atomic_destroy_state callback

In the Linux kernel, the following vulnerability has been resolved:

drm/atmel-hlcdc: fix memory leak from the atomic_destroy_state callback

After several commits, the slab memory increases. Some drm_crtc_commit

objects are not freed. The atomic_destroy_state callback only put the

framebuffer. Use the __drm_atomic_helper_plane_destroy_state() function

to put all the objects that are no longer needed.

It has been seen after hours of usage of a graphics application or using

kmemleak:

unreferenced object 0xc63a6580 (size 64):

comm "egt_basic", pid 171, jiffies 4294940784

hex dump (first 32 bytes):

40 50 34 c5 01 00 00 00 ff ff ff ff 8c 65 3a c6 @P4..........e:.

8c 65 3a c6 ff ff ff ff 98 65 3a c6 98 65 3a c6 .e:......e:..e:.

backtrace (crc c25aa925):

kmemleak_alloc+0x34/0x3c

__kmalloc_cache_noprof+0x150/0x1a4

drm_atomic_helper_setup_commit+0x1e8/0x7bc

drm_atomic_helper_commit+0x3c/0x15c

drm_atomic_commit+0xc0/0xf4

drm_atomic_helper_set_config+0x84/0xb8

drm_mode_setcrtc+0x32c/0x810

drm_ioctl+0x20c/0x488

sys_ioctl+0x14c/0xc20

ret_fast_syscall+0x0/0x54