RISC-V: Mark IORESOURCE_EXCLUSIVE for reserved mem instead of IORESOURCE_BUSY

RISC-V: Mark IORESOURCE_EXCLUSIVE for reserved mem instead of IORESOURCE_BUSY

Commit 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree")
marked IORESOURCE_BUSY for reserved memory, which caused resource map
failed in subsequent operations of related driver, so remove the
IORESOURCE_BUSY flag. In order to prohibit userland mapping reserved
memory, mark IORESOURCE_EXCLUSIVE for it.

The code to reproduce the issue,
dts:
        mem0: memory@a0000000 {
                reg = <0x0 0xa0000000 0 0x1000000>;
                no-map;
        };

        &test {
                status = "okay";
                memory-region = <&mem0>;
        };

code:
        np = of_parse_phandle(pdev->dev.of_node, "memory-region", 0);
        ret = of_address_to_resource(np, 0, &r);
        base = devm_ioremap_resource(&pdev->dev, &r);
        // base = -EBUSY

Fixes: 00ab027a3b82 ("RISC-V: Add kernel image sections to the resource tree")
Reported-by: Huaming Jiang <jianghuaming.jhm@alibaba-inc.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Co-developed-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220518013428.1338983-1-xianting.tian@linux.alibaba.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>