BPI M1 hangs at mounting root filesystem from SATA disk since r345948

[qroxana]

Here's the boot message of r345948:

ada0: 150.000MB/s transfers (SATA 1.x, UDMA5, PIO 8192bytes)
ada0: Command Queueing enabled
ada0: 76319MB (156301488 512 byte sectors)
GEOM: new disk ada0
mmc0: Card at relative address 0x1234 added:
mmc0:  card: SDHC SA08G 2.1 SN 44E37D57 MFG 11/2015 by 2 TM
mmc0:  quirks: 0
mmc0:  bus: 4bit, 50MHz (high speed timing)
mmc0:  memory: 15196160 blocks, erase sector 8192 blocks
mmc0: setting transfer rate to 50.000MHz (high speed timing)
mmcsd0: 8GB <SDHC SA08G 2.1 SN 44E37D57 MFG 11/2015 by 2 TM> at mmc0 50.0MHz/4bit/32768-block
Release APs
CPU(1) applied BP hardening: not necessary
arc4random: no preloaded entropy cache
regulator: shutting down vcc3v0
Trying to mount root from ufs:/dev/label/root [rw]...
regulator: shutting down vcc3v3
regulator: shutting down vcc5v0
regulator: shutting down ldo3

r345947 boots fine.