ahci: mediatek: fix undefined reference of dev_err

ahci: mediatek: fix undefined reference of dev_err

building with MTK_AHCI enabled results in implicit declaration and
undefined reference of dev_err followed by a segfault of gcc

drivers/ata/mtk_ahci.c: In function 'mtk_ahci_parse_property':
drivers/ata/mtk_ahci.c:65:4: warning:
implicit declaration of function 'dev_err'
drivers/ata/mtk_ahci.c:65: undefined reference to `dev_err'
in function `mtk_ahci_probe':
drivers/ata/mtk_ahci.c:92: undefined reference to `dev_err'
Segmentation fault

fix this by adding the dm/device_compat.h to includes

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>