This patch adds inter-processor interrupt support using K230 mailbox
device to improve the RPMsg efficiency. The polling logic has been
dropped.
Major changes:
- in arch/risc-v/include/k230:
- irq.h add IRQ for IPI devices
- in arch/risc-v/src/k230:
- Kconfig add IPI related config, increase polling delay
- Make.defs add k230_ipi.c to CHIP_SRCS
- k230_hart.c fix typo, add notes of zero MISA reading w/ NUTTSBI
- k230_irq.c use K230_PLIC_IRQS as ext IRQ limit to support IPI
- k230_rptun.c use IPI instead of polling
- in boards/risc-v/k230/canmv230/configs
- master enable IPI support
- remote enable IPI, TMPFS, RPMSGFS etc
New additions:
- in arch/risc-v/src/k230:
- k230_ipi.h add K230 IPI related defintions
- k230_ipi.c add K230 IPI driver
Signed-off-by: Yanfeng Liu <yfliu2008@qq.com>