feat(stm32mp15): remove OP-TEE shared mem

The flag STM32MP15_OPTEE_RSV_SHM was disabled and mark deprecated.
Remove the corresponding code.

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: I948af3e1de4b89815c967a63abe64f285c405ecc
diff --git a/docs/about/release-information.rst b/docs/about/release-information.rst
index a5fd1d6..7fafe03 100644
--- a/docs/about/release-information.rst
+++ b/docs/about/release-information.rst
@@ -83,7 +83,7 @@
 |                                | Date        | after   |                                                         |
 |                                |             | Release |                                                         |
 +================================+=============+=========+=========================================================+
-| STM32MP15_OPTEE_RSV_SHM        |     2.10    |   3.0   | OP-TEE manages its own memory on STM32MP15              |
+|                                |             |         |                                                         |
 +--------------------------------+-------------+---------+---------------------------------------------------------+
 
 Removal of Deprecated Drivers