memset is an optimized operation that at least on ARM64 may only be
called on cached memory, see 32e8842c40 ("ARM: lib64: Make string
functions aware of MMU configuration"). To avoid crashes in the ehci
driver we no longer call memset on memory allocated with
dma_alloc_coherent(), but use a simple memzero32 function instead.

Reported-by: Elmar Albert <EAlbert@data-modul.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>