ArmPkg/ArmTrngLib: Remove ASSERT in GetArmTrngVersion()

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4150

GetArmTrngVersion() is used to check the presence of an Arm
Trng. If not found, an ASSERT prevents from booting in DEBUG
builds.
Remove this ASSERT.

Reported-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

ArmPkg/Library/ArmTrngLib/ArmTrngLib.c

@@ -344,7 +344,6 @@ ArmTrngLibConstructor (
 
   Status = GetArmTrngVersion (&MajorRev, &MinorRev);
   if (RETURN_ERROR (Status)) {
-    ASSERT_RETURN_ERROR (Status);
     goto ErrorHandler;
   }