This patch fixes up minor typos in ibex_spi_host

Signed-off-by: Wilfred Mallawa <wilfred.mallawa@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Message-Id: <20220823061201.132342-2-wilfred.mallawa@opensource.wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>