If x1/x4 mode is not set correctly then link with endpoint card is not
established.

Use DTS property 'num-lanes' to deteriminate x1/x4 mode.

Link: https://lore.kernel.org/r/20220222155030.988-6-pali@kernel.orgSigned-off-by: NPali Rohár <pali@kernel.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>