powerpc: move the ARCH_DMA_MINALIGN definition to asm/cache.h

Patch series "Move the ARCH_DMA_MINALIGN definition to asm/cache.h".

The ARCH_KMALLOC_MINALIGN reduction series defines a generic
ARCH_DMA_MINALIGN in linux/cache.h:

https://lore.kernel.org/r/20230612153201.554742-2-catalin.marinas@arm.com/

Unfortunately, this causes a duplicate definition warning for
microblaze, powerpc (32-bit only) and sh as these architectures define
ARCH_DMA_MINALIGN in a different file than asm/cache.h. Move the macro
to asm/cache.h to avoid this issue and also bring them in line with the
other architectures.


This patch (of 3):

The powerpc architecture defines ARCH_DMA_MINALIGN in asm/page_32.h and
only if CONFIG_NOT_COHERENT_CACHE is enabled (32-bit platforms only). 
Move this macro to asm/cache.h to allow a generic ARCH_DMA_MINALIGN
definition in linux/cache.h without redefine errors/warnings.

Link: https://lkml.kernel.org/r/20230613155245.1228274-1-catalin.marinas@arm.com
Link: https://lkml.kernel.org/r/20230613155245.1228274-2-catalin.marinas@arm.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306131053.1ybvRRhO-lkp@intel.com/


Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Rich Felker <dalias@libc.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>