beckham: Drop support for building twrp

* No this doesn't break twrp support in any way, twrp will still work.
  All this does is remove the makefiles to build twrp using this device
  tree which we don't currently do anyway, so removing for now.

Change-Id: Icd4403e5b73c5aec977a6d5afa31720703eb9b39
Signed-off-by: Joshua Blanchard <joshua.lee.bbg@gmail.com>

lineage_beckham.mk

@@ -59,12 +59,8 @@ PRODUCT_PACKAGES += \
     bootctrl.sdm660 \
     bootctrl.sdm660.recovery
 
-# TWRP
-ifeq ($(WITH_TWRP),true)
-    $(call inherit-product, device/motorola/beckham/twrp/twrp.mk)
-else
-    TARGET_RECOVERY_FSTAB := device/motorola/sdm660-common/rootdir/etc/fstab.qcom
-endif
+# Recovery
+TARGET_RECOVERY_FSTAB := device/motorola/sdm660-common/rootdir/etc/fstab.qcom
 
 # Device identifiers
 PRODUCT_DEVICE := beckham

twrp/twrp.fstab

-/boot            emmc              /dev/block/bootdevice/by-name/boot       flags=slotselect
-/system          ext4              /dev/block/bootdevice/by-name/system     flags=slotselect
-/system_image    emmc              /dev/block/bootdevice/by-name/system     flags=slotselect
-/data            ext4              /dev/block/bootdevice/by-name/userdata
-
-#/usb-otg         vfat              /dev/block/sdg1      /dev/block/sdg              flags=removable;storage;display=USB-OTG

twrp/twrp.mk

-RECOVERY_SDCARD_ON_DATA := true
-TARGET_RECOVERY_FSTAB := device/motorola/beckham/twrp/twrp.fstab
-TARGET_RECOVERY_QCOM_RTC_FIX := true
-TARGET_RECOVERY_PIXEL_FORMAT := "RGBX_8888"
-TARGET_USES_LOGD := true
-TW_CRYPTO_USE_SYSTEM_VOLD := qseecomd
-TW_EXCLUDE_DEFAULT_USB_INIT := true
-TW_EXCLUDE_SUPERSU := true
-TW_DEFAULT_BRIGHTNESS := 149
-TW_INCLUDE_CRYPTO := true
-TW_INPUT_BLACKLIST := "hbtp_vm"
-TW_MAX_BRIGHTNESS := 255
-TW_SCREEN_BLANK_ON_BOOT := true
-TW_THEME := portrait_hdpi
-TWRP_INCLUDE_LOGCAT := true
-TARGET_USE_CUSTOM_LUN_FILE_PATH := "/sys/devices/soc/a800000.ssusb/a800000.dwc3/gadget/lun%d/file"
-#TW_BRIGHTNESS_PATH := "/sys/devices/soc/900000.qcom\x2cmdss_mdp/900000.qcom\x2cmdss_mdp:qcom\x2cmdss_fb_primary/leds/lcd-backlight/brightness"
-#TARGET_HW_DISK_ENCRYPTION := true
-#TARGET_KEYMASTER_WAIT_FOR_QSEE := true