lib: sbi_pmu: move pmu irq information into pmu itself

Don't spread checking for pmu extensions through the code
but instead introduce a sbi-pmu function that other code can
call to get the correct information about the existence of the
pmu interrupt.

Add a sbi_pmu_device override function to allow overridung this
bit as well if needed.

Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

include/sbi/sbi_pmu.h

@@ -73,6 +73,11 @@ struct sbi_pmu_device {
 	 * Note: 0 <= counter_index < SBI_PMU_HW_CTR_MAX
 	 */
 	void (*hw_counter_disable_irq)(uint32_t counter_index);
+
+	/**
+	 * Custom function returning the machine-specific irq-bit.
+	 */
+	int (*hw_counter_irq_bit)(void);
 };
 
 /** Get the PMU platform device */
@@ -87,6 +92,9 @@ int sbi_pmu_init(struct sbi_scratch *scratch, bool cold_boot);
 /** Reset PMU during hart exit */
 void sbi_pmu_exit(struct sbi_scratch *scratch);
 
+/** Return the pmu irq bit depending on extension existence */
+int sbi_pmu_irq_bit(void);
+
 /**
  * Add the hardware event to counter mapping information. This should be called
  * from the platform code to update the mapping table.