ShellPkg: acpiview: MADT: Prevent buffer overruns

Modify the parsing logic to prevent reading past the MADT table buffer
length provided when parsing the Interrupt Controller Structure header.

Signed-off-by: Krzysztof Koch <krzysztof.koch@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
Reviewed-by: Zhichao Gao <zhichao.gao@inte.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Madt/MadtParser.c

@@ -256,7 +256,7 @@ ParseAcpiMadt (
       0,
       NULL,
       InterruptContollerPtr,
-      2,  //  Length is 1 byte at offset 1
+      AcpiTableLength - Offset,
       PARSER_PARAMS (MadtInterruptControllerHeaderParser)
       );