arm64: kernel: add code to set cpu boot mode to secondary_entry shim

The refactoring of el2_setup split code setting up EL2 and detecting the
CPU boot mode in separate chunks. This allows the code that sets up EL2 to
run in an endian independent way - ie before the endianess is set up in
the respective sctlr registers.

This patch brings secondary_entry up-to-date so that CPUs entering the
kernel through this code path set-up EL2 and the cpu boot mode properly.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: NMark Rutland <mark.rutand@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/head.S

@@ -282,8 +282,9 @@ ENDPROC(secondary_holding_pen)
 	 * be used where CPUs are brought online dynamically by the kernel.
 	 */
 ENTRY(secondary_entry)
-	bl	__calc_phys_offset		// x2=phys offset
 	bl	el2_setup			// Drop to EL1
+	bl	__calc_phys_offset		// x24=PHYS_OFFSET, x28=PHYS_OFFSET-PAGE_OFFSET
+	bl	set_cpu_boot_mode_flag
 	b	secondary_startup
 ENDPROC(secondary_entry)