Revert "initrd.scripts: busybox depmod doesn't support -v even though it declares so"

This reverts commit f3570c39577573b3dcd8c77720a292fa6b89a022.
Revert "linuxrc: add depmod call as workaround for missing modules.dep.bb"

This reverts commit ece907ea64c3655854cd4044ed33c5d22d8ca463.
busybox: switch away from MODPROBE_SMALL, see bug #472312#c27
busybox: issue a full make menuconfig against busybox 1.21