Move `PSR_Off` out of `Power_And_Clocks_Haswell`

Allowing other platforms to use the Haswell-specific power and clocks
package precludes with'ing other Haswell-specific units unless they are
placed under `haswell_shared` as well. This unnecessarily forces several
implementation-specific details to be public, breaking encapsulation.

The only benefit is that the `PSR_Off` procedure gets to be shared.
However, we can allow reusing said procedure without having to destroy
encapsulation, by moving it elsewhere. As the SRD/PSR registers are tied
to transcoders, place `PSR_Off` and the corresponding definitions to the
common `Transcoder` package. Also update the callers of this procedure
to refer to the `Transcoder` package, and then drop the visibility of
the power and clocks package for Haswell.

Change-Id: I7483409b8b7db58874cbba3c0a7edb1968bba456
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/libgfxinit/+/43563
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/common/haswell/Makefile.inc b/common/haswell/Makefile.inc
index a75c189..ef75dc4 100644
--- a/common/haswell/Makefile.inc
+++ b/common/haswell/Makefile.inc
@@ -7,5 +7,7 @@
 gfxinit-y += hw-gfx-gma-plls.adb
 gfxinit-y += hw-gfx-gma-plls.ads
 gfxinit-y += hw-gfx-gma-power_and_clocks.ads
+gfxinit-y += hw-gfx-gma-power_and_clocks_haswell.adb
+gfxinit-y += hw-gfx-gma-power_and_clocks_haswell.ads
 gfxinit-y += hw-gfx-gma-spll.adb
 gfxinit-y += hw-gfx-gma-spll.ads