Doc: Remove useless escape characters

Just like has been done in the porting guide a couple of patches
earlier, kill all escaped underscore characters in all documents.

Change-Id: I7fb5b806412849761d9221a6ce3cbd95ec43d611
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/docs/trusted-board-boot.rst b/docs/trusted-board-boot.rst
index 5ab32fe..33005e3 100644
--- a/docs/trusted-board-boot.rst
+++ b/docs/trusted-board-boot.rst
@@ -59,7 +59,7 @@
 -  **Trusted world key**
 
    The private part is used to sign the key certificates corresponding to the
-   secure world images (SCP\_BL2, BL31 and BL32). The public part is stored in
+   secure world images (SCP_BL2, BL31 and BL32). The public part is stored in
    one of the extension fields in the trusted world certificate.
 
 -  **Non-trusted world key**
@@ -70,7 +70,7 @@
 
 -  **BL3-X keys**
 
-   For each of SCP\_BL2, BL31, BL32 and BL33, the private part is used to
+   For each of SCP_BL2, BL31, BL32 and BL33, the private part is used to
    sign the content certificate for the BL3-X image. The public part is stored
    in one of the extension fields in the corresponding key certificate.
 
@@ -78,7 +78,7 @@
 
 -  BL1
 -  BL2
--  SCP\_BL2 (optional)
+-  SCP_BL2 (optional)
 -  BL31
 -  BL33
 -  BL32 (optional)
@@ -96,14 +96,14 @@
    public part of the trusted world key and the public part of the non-trusted
    world key.
 
--  **SCP\_BL2 key certificate**
+-  **SCP_BL2 key certificate**
 
    It is self-signed with the trusted world key. It contains the public part of
-   the SCP\_BL2 key.
+   the SCP_BL2 key.
 
--  **SCP\_BL2 content certificate**
+-  **SCP_BL2 content certificate**
 
-   It is self-signed with the SCP\_BL2 key. It contains a hash of the SCP\_BL2
+   It is self-signed with the SCP_BL2 key. It contains a hash of the SCP_BL2
    image.
 
 -  **BL31 key certificate**
@@ -133,8 +133,8 @@
 
    It is self-signed with the BL33 key. It contains a hash of the BL33 image.
 
-The SCP\_BL2 and BL32 certificates are optional, but they must be present if the
-corresponding SCP\_BL2 or BL32 images are present.
+The SCP_BL2 and BL32 certificates are optional, but they must be present if the
+corresponding SCP_BL2 or BL32 images are present.
 
 Trusted Board Boot Sequence
 ---------------------------
@@ -160,8 +160,8 @@
    registers. If the comparison succeeds, BL2 reads and saves the trusted and
    non-trusted world public keys from the verified certificate.
 
-The next two steps are executed for each of the SCP\_BL2, BL31 & BL32 images.
-The steps for the optional SCP\_BL2 and BL32 images are skipped if these images
+The next two steps are executed for each of the SCP_BL2, BL31 & BL32 images.
+The steps for the optional SCP_BL2 and BL32 images are skipped if these images
 are not present.
 
 -  BL2 loads and verifies the BL3x key certificate. The certificate signature