risc-v/k230: add IPI support to speed up RPTUN/RPMSG

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>

boards/risc-v/k230/canmv230/configs/remote/defconfig

@@ -31,7 +31,6 @@ CONFIG_ARCH_USE_MMU=y
 CONFIG_ARCH_USE_MPU=y
 CONFIG_ARCH_USE_S_MODE=y
 CONFIG_BINFMT_ELF_EXECUTABLE=y
-CONFIG_BLK_RPMSG=y
 CONFIG_BOARD_LATE_INITIALIZE=y
 CONFIG_BOARD_LOOPSPERMSEC=6366
 CONFIG_BUILD_KERNEL=y
@@ -42,6 +41,8 @@ CONFIG_DEV_ZERO=y
 CONFIG_ELF=y
 CONFIG_FS_PROCFS=y
 CONFIG_FS_ROMFS=y
+CONFIG_FS_RPMSGFS=y
+CONFIG_FS_TMPFS=y
 CONFIG_IDLETHREAD_STACKSIZE=3072
 CONFIG_INIT_FILEPATH="/system/bin/init"
 CONFIG_INIT_MOUNT=y
@@ -71,6 +72,7 @@ CONFIG_RAM_SIZE=16777216
 CONFIG_RAM_START=0x7000000
 CONFIG_RAW_BINARY=y
 CONFIG_READLINE_CMD_HISTORY=y
+CONFIG_RPMSG_PING=y
 CONFIG_RPMSG_UART=y
 CONFIG_RPMSG_UART_CONSOLE=y
 CONFIG_RPTUN=y
@@ -85,5 +87,4 @@ CONFIG_START_YEAR=2024
 CONFIG_SYMTAB_ORDEREDBYNAME=y
 CONFIG_SYSTEM_NSH=y
 CONFIG_SYSTEM_NSH_PROGNAME="init"
-CONFIG_TESTING_GETPRIME=y
 CONFIG_USEC_PER_TICK=1000