common: Remove invalid endianess conversion

common: Remove invalid endianess conversion

do_bootm_standanlone() calls ntohl(images->ep) which is wrong because
endianess conversion has already been done:

do_bootm()
\-do_bootm_states()
  +-bootm_find_os()
  | \-images.ep = image_get_ep();
  |   \-uimage_to_cpu(hdr->ih_ep);
  \-boot_selected_os()
    \-do_bootm_standanlone()

Without this conversion the code works correctly at least on AT91SAM9G45.
On big endian systems there should be no difference after applying this
patch because uimage_to_cpu(x) and ntohl(x) both expand to 'x'.

Signed-off-by: Christian Eggers <ceggers@gmx.de>