ArmPkg/AsmMacroIoLibV8: remove undocumented assumption from ELx macros

ArmPkg/AsmMacroIoLibV8: remove undocumented assumption from ELx macros

The macros EL1_OR_EL2() and EL1_OR_EL2_OR_EL3() allow conditional execution
of assembly sequences based on the current exception level, by jumping to
caller supplied labels 1f, 2f or 3f. However, the jump to 1f is actually
a fallthrough, which means the EL1 code needs to follow right after the
macro invocation, and the 1f label is ignored.

So let's fix this by making all jumps explicit.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Eugene Cohen <eugene@hp.com>