arm: ti: boot: Remove legacy Android partitions

Remove unused Android partitions:
  - efs, crypto, cache: we don't use it anymore (images are not built
    in AOSP
  - ipu1, ipu2: IPU firmware is now a part of vendor image and doesn't
    reside as a separate partition

While at it, rename "reserved" partition to "uboot-env", as it's
actually stores U-Boot environment.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Praneeth Bajjuri <praneeth@ti.com>