Merge 5.4.256 into android11-5.4-lts

Changes in 5.4.256
	powerpc/pmac/smp: Avoid unused-variable warnings
	powerpc/pmac/smp: Drop unnecessary volatile qualifier
	Revert "MIPS: Alchemy: fix dbdma2"
	Linux 5.4.256

Change-Id: Id963efe437b2c99033d2ae4496b1081333f628bb
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>