nvme: Do not allocate 8kB buffer on stack

Calling 'nvme scan' followed by 'nvme detail' crashes U-Boot on Turris
Omnia with the following error:

  undefined instruction
  pc : [<0a000000>]          lr : [<7ff80bfc>]
  reloc pc : [<8a8c0000>]    lr : [<00840bfc>]
  sp : 7fb2b908  ip : 0000002a     fp : 02000000
  r10: 04000000  r9 : 7fb2fed0     r8 : e1000000
  r7 : 0c000000  r6 : 03000000     r5 : 06000000  r4 : 01000000
  r3 : 7fb30928  r2 : 7fb30928     r1 : 00000000  r0 : 00000000
  Flags: nZCv  IRQs off  FIQs off  Mode SVC_32
  Code: 0f0fb4f0 0f0fb4f0 0f0fb4f0 0f0fb4f0 (f0f04b0f)
  Resetting CPU ...

This happens when nvme_print_info() tries to return to the caller. It
looks like this error is caused by trying to allocate 8 KiB of memory
on the stack by the two uses of ALLOC_CACHE_ALIGN_BUFFER().

Use malloc_cache_aligned() to allocate this memory dynamically instead.

This fixes 'nvme detail' on Turris Omnia.

Note that similar change was applied to file drivers/nvme/nvme.c in past by
commit 2f83481d ("nvme: use page-aligned buffer for identify command").

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <marek.behun@nic.cz>