grub.cfg: Add arguments to kernel cmdline
grub.cfg: Add arguments to kernel cmdline

Add otherbootargs, usb_gadget_arg to kernel cmdline

Signed-off-by: Chaitanya Vadrevu <3811a3cb328197c46ad44d4be31bbd66ea52bfbb@ni.com>

ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt