ANDROID: mm/slab: Create 64-byte slab caches if the hardware supports it

Currently, ARM64 hardcodes ARCH_DMA_MINALIGN to 128 bytes, which
ultimately causes the smallest kmalloc cache in the system to allocate
128 byte objects. This is wasteful on systems that don't have this 128
byte minimum DMA alignment requirement, as their cachelines are 64 bytes
in size, and thus, can function properly with kmalloc allocating objects
64 bytes in size.

Add a commandline parameter--android_kmalloc_64_create--to create and use
all of the different types of kmalloc caches (e.g. kmalloc-*,
kmalloc-rcl-*, etc) for 64-byte allocations, if the hardware supports it.
The hardware supports 64 byte objects if their size is aligned to the cache
line size that is reported by the system.

This patch is loosely based on the discussion in [1] and aims to
optimize the amount of memory kmalloc uses by allowing slab allocations
to be satisfied by the kmalloc-64 cache, if the hardware supports it.

This approach differs from [1] by being less invasive, and only attempting
to create the kmalloc-64 cache if the kmalloc_64_create parameter is
specified in the kernel commandline. The intent of this is to preserve
the ABI semantics of kmalloc (i.e. 128 or ARCH_DMA_MINALIGN byte alignment)
for existing devices using ARM64 GKI kernels on the android13-5.15 branch,
since the KMI is frozen.

The final solution from [1] should be used, or this patch should be
reworked for future versions of Android and should not be cherry-picked
forward.

[1] https://lore.kernel.org/linux-mm/20220405135758.774016-1-catalin.marinas@arm.com/



Bug: 241844128
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Change-Id: I6d39e6c6957c944f0327e6774afd33f4c2230019