arm64: Use existing defines for mdscr

Literal values are being used to set single stepping in mdscr from assembly
code. There are already existing defines representing those values, use
those instead of the literal values.
Signed-off-by: NJulien Thierry <julien.thierry@arm.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arch/arm64/include/asm/assembler.h

@@ -25,6 +25,7 @@
 
 #include <asm/asm-offsets.h>
 #include <asm/cpufeature.h>
+#include <asm/debug-monitors.h>
 #include <asm/mmu_context.h>
 #include <asm/page.h>
 #include <asm/pgtable-hwdef.h>
@@ -65,7 +66,7 @@
 	.macro	disable_step_tsk, flgs, tmp
 	tbz	\flgs, #TIF_SINGLESTEP, 9990f
 	mrs	\tmp, mdscr_el1
-	bic	\tmp, \tmp, #1
+	bic	\tmp, \tmp, #DBG_MDSCR_SS
 	msr	mdscr_el1, \tmp
 	isb	// Synchronise with enable_dbg
 9990:
@@ -75,7 +76,7 @@
 	tbz	\flgs, #TIF_SINGLESTEP, 9990f
 	disable_dbg
 	mrs	\tmp, mdscr_el1
-	orr	\tmp, \tmp, #1
+	orr	\tmp, \tmp, #DBG_MDSCR_SS
 	msr	mdscr_el1, \tmp
 9990:
 	.endm