powerpc: mpc8xx: harmonise initialisation of the immap local pointer

In most places, immap local pointer is defined as
	immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR;
In a few places, it is defined as
	immap_t __iomem *immap = (immap_t __iomem *)(immr & 0xFFFF0000);

This patch replaces the few of the latest form by the other one.

The two are fully equivalent since SPRN_IMMR is set with CONFIG_SYS_IMMR
very early in start.S

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

arch/powerpc/cpu/mpc8xx/cpu.c

@@ -36,7 +36,7 @@ DECLARE_GLOBAL_DATA_PTR;
 
 static int check_CPU(long clock, uint pvr, uint immr)
 {
-	immap_t __iomem *immap = (immap_t __iomem *)(immr & 0xFFFF0000);
+	immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR;
 	uint k;
 	char buf[32];
 
@@ -237,8 +237,7 @@ int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  */
 unsigned long get_tbclk(void)
 {
-	uint immr = get_immr(0);	/* Return full IMMR contents */
-	immap_t __iomem *immap = (immap_t __iomem *)(immr & 0xFFFF0000);
+	immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR;
 	ulong oscclk, factor, pll;
 
 	if (in_be32(&immap->im_clkrst.car_sccr) & SCCR_TBS)

arch/powerpc/cpu/mpc8xx/speed.c

@@ -17,8 +17,7 @@ DECLARE_GLOBAL_DATA_PTR;
  */
 int get_clocks(void)
 {
-	uint immr = get_immr(0);	/* Return full IMMR contents */
-	immap_t __iomem *immap = (immap_t __iomem *)(immr & 0xFFFF0000);
+	immap_t __iomem *immap = (immap_t __iomem *)CONFIG_SYS_IMMR;
 	uint sccr = in_be32(&immap->im_clkrst.car_sccr);
 	uint divider = 1 << (((sccr & SCCR_DFBRG11) >> 11) * 2);