ARM: OMAP4+: PRM: determine prm_device_inst based on DT compatibility

PRM device instance offset is now provided through the prm_init_data.
This gets rid of some cpu_is_X / soc_is_X calls from PRM core code,
preparing for PRM to be its own separate driver.

Signed-off-by: Tero Kristo <t-kristo@ti.com>

arch/arm/mach-omap2/prcm-common.h

@@ -524,6 +524,7 @@ struct omap_prcm_irq_setup {
  * @mem: IO mem pointer for this module
  * @offset: module base address offset from the IO base
  * @flags: PRCM module init flags
+ * @device_inst_offset: device instance offset within the module address space
  * @init: low level PRCM init function for this module
  * @np: device node for this PRCM module
  */
@@ -532,6 +533,7 @@ struct omap_prcm_init_data {
 	void __iomem *mem;
 	s16 offset;
 	u16 flags;
+	s32 device_inst_offset;
 	int (*init)(const struct omap_prcm_init_data *data);
 	struct device_node *np;
 };