soc/amd/common/block/acpi/cpu_power_state: use pstate_msr union

Use the pstate_msr union in get_pstate_info to check if the P state
enable bit is set. Also drop the now unused PSTATE_DEF_HI_ENABLE_SHIFT
and PSTATE_DEF_HI_ENABLE_MASK definitions.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I79119e09af79a4bb680a18e93b4a61a049f0080e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73925
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Fred Reitberger <reitbergerfred@gmail.com>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>

src/include/cpu/amd/msr.h

@@ -41,8 +41,6 @@
 #define PS_STS_REG			0xC0010063
 #define PSTATE_0_MSR			0xC0010064
 #define PSTATE_MSR(pstate)		(PSTATE_0_MSR + (pstate))
-#define  PSTATE_DEF_HI_ENABLE_SHIFT	31
-#define  PSTATE_DEF_HI_ENABLE_MASK	(0x1 << PSTATE_DEF_HI_ENABLE_SHIFT)
 
 #define MSR_PATCH_LOADER		0xC0010020