arm64: defconfig: Update UFSHCD for Hi3660 soc

Commit 7ee7ef24 ("scsi: arm64: defconfig: enable configs for Hisilicon ufs")
set 'CONFIG_SCSI_UFS_HISI=y', but the configs it depends
on

  (CONFIG_SCSI_HFSHCD_PLATFORM && CONFIG_SCSI_UFSHCD)

were left to being built as modules.

commit 1f4fa50d ("arm64: defconfig: Regenerate for v4.20") "fixed"
that by reverting to 'CONFIG_SCSI_UFS_HISI=m'.

Thing is, if the rootfs is stored in the on-board flash (which
is the "canonical" way of doing things), we either need these drivers
to be built-in, or we need to fiddle with an initramfs to access that
flash and eventually load the modules installed over there.

The former is the easiest, do that.

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>