Revert "mt76: probe load mt7615 driver asynchronously"

This reverts commit 8176431963 ("mt76: probe load mt7615 driver
asynchronously").  After said commit, users report that MT7615 no longer
works on boot and they have to manually enable WiFi (via command "wifi") to
make it working again.

Fixes: FS#2546
Ref: https://forum.openwrt.org/t/xiaomi-r3p-no-wifi-on-boot/45509
Signed-off-by: DENG Qingfang <dengqf6@mail2.sysu.edu.cn>
[commit description facelift]
Signed-off-by: Petr Štetiar <ynezz@true.cz>

package/kernel/mt76/Makefile

@@ -144,7 +144,6 @@ define KernelPackage/mt7615e
   DEPENDS+=@PCI_SUPPORT +kmod-mt76-core
   FILES:=\
 	$(PKG_BUILD_DIR)/mt7615/mt7615e.ko
-  MODPARAMS:=async_probe
   AUTOLOAD:=$(call AutoProbe,mt7615e)
 endef