ArmPkg/ArmLib: Add ArmHasEte () helper function

Create a helper function to query whether ID_AA64MFR1_EL1 indicates
presence of the Embedded Trace Extension (ETE). This feature is only
visible in AARCH64 state.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Cc: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>

ArmPkg/Include/Library/ArmLib.h

@@ -793,6 +793,18 @@ ArmHasTrbe (
   VOID
   );
 
+/**
+  Checks whether the CPU implements the Embedded Trace Extension.
+
+  @retval TRUE  FEAT_ETE is implemented.
+  @retval FALSE FEAT_ETE is not mplemented.
+**/
+BOOLEAN
+EFIAPI
+ArmHasEte (
+  VOID
+  );
+
 #endif // MDE_CPU_AARCH64
 
 #ifdef MDE_CPU_ARM