chore(bl): add UNALIGNED symbols for TEXT/RODATA

Add symbols to mark end of TEXT/RODATA before page alignment.
Similar change was done by commit 8d69a03f6a7d ("Various
improvements/cleanups on the linker scripts") for
RO_END/COHERENT_RAM. These symbols help to know how much free
space is in the final binary because of page alignment.

Also show all *UNALIGNED__ symbols via poetry.
For example:
poetry run memory -p zynqmp -b debug

Change-Id: I322beba37dad76be9f4e88ca7e5b3eff2df7d96e
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/docs/design/firmware-design.rst b/docs/design/firmware-design.rst
index 998824f..50839bd 100644
--- a/docs/design/firmware-design.rst
+++ b/docs/design/firmware-design.rst
@@ -1559,8 +1559,10 @@
 -  ``__RO_START__``
 -  ``__RO_END__``
 -  ``__TEXT_START__``
+-  ``__TEXT_END_UNALIGNED__``
 -  ``__TEXT_END__``
 -  ``__RODATA_START__``
+-  ``__RODATA_END_UNALIGNED__``
 -  ``__RODATA_END__``
 
 BL1's linker symbols