usb: gadget: mass_storage: added sysfs entry for cdrom to LUNs#4

FrozenCow wants to merge 1 commit intoOnePlusOSS:5.1.1OnePlusOSS/android_kernel_oneplus_msm8994:5.1.1from

FrozenCow:OnePlusOSS_oneplus_msm8994_5.1.1_gadget_cdromFrozenCow/android_kernel_oneplus_msm8994:OnePlusOSS_oneplus_msm8994_5.1.1_gadget_cdromCopy head branch name to clipboard