rtc: mpc5121: replace in_8/out_8 with generic accessors

Convert the PowerPC-specific in_8/out_8, in_be16/out_be16 and in_be32/out_be32 accessors to the portable ioread8/iowrite8, ioread16be/iowrite16be and ioread32be/iowrite32be. On PowerPC these use the same ordered MMIO accessors, so behaviour is unchanged.

With no PowerPC-only accessors left, allow COMPILE_TEST, and add the HAS_IOMEM dependency the generic accessors need.

---
 drivers/rtc/Kconfig       |  3 +-
 drivers/rtc/rtc-mpc5121.c | 80 +++++++++++++++++++--------------------
 2 files changed, 42 insertions(+), 41 deletions(-)

index 0636b9ead2c2..8c0ac7e7a582 100644
@@ -1773,7 +1773,8 @@ config RTC_DRV_MC13XXX
 
 config RTC_DRV_MPC5121
 	tristate "Freescale MPC5121 built-in RTC"
-	depends on PPC_MPC512x || PPC_MPC52xx
+	depends on PPC_MPC512x || PPC_MPC52xx || COMPILE_TEST
+	depends on HAS_IOMEM
 	help
 	  If you say yes here you will get support for the
 	  built-in RTC on MPC5121 or on MPC5200.

2.56.0