ARM: imx: Drop board side icache enable on Data Modul i.MX8M Mini eDM SBC

The icache is enabled in common architecture code since commit:
2fa763baa1c ("ARM: imx: Enable instruction cache early on on i.MX8M")
Drop the board side duplicate code.

Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/board/data_modul/imx8mm_edm_sbc/imx8mm_data_modul_edm_sbc.c b/board/data_modul/imx8mm_edm_sbc/imx8mm_data_modul_edm_sbc.c
index dc08830..82856f7 100644
--- a/board/data_modul/imx8mm_edm_sbc/imx8mm_data_modul_edm_sbc.c
+++ b/board/data_modul/imx8mm_edm_sbc/imx8mm_data_modul_edm_sbc.c
@@ -19,12 +19,6 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-int mach_cpu_init(void)
-{
-	icache_enable();
-	return 0;
-}
-
 int board_phys_sdram_size(phys_size_t *size)
 {
 	u8 memcfg = dmo_get_memcfg();