arch-arm: Fix semihosting arg count for SYS_GET_CMDLINE

SYS_GET_CMDLINE was declared as having 1 parameter when it is really
supposed to have two parameters.

Change-Id: Ia364abb4b34834f4d5e598b5adee9585e0815ac8
Reported-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Jack Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/10022
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
diff --git a/src/arch/arm/semihosting.cc b/src/arch/arm/semihosting.cc
index 46d964d..51107cb 100644
--- a/src/arch/arm/semihosting.cc
+++ b/src/arch/arm/semihosting.cc
@@ -76,7 +76,7 @@
     { 0x11, { "SYS_TIME", &ArmSemihosting::callTime, 0, 0} },
     { 0x12, { "SYS_SYSTEM", &ArmSemihosting::callSystem, 2, 2} },
     { 0x13, { "SYS_ERRNO", &ArmSemihosting::callErrno, 0, 0 } },
-    { 0x15, { "SYS_GET_CMDLINE", &ArmSemihosting::callGetCmdLine, 1, 1} },
+    { 0x15, { "SYS_GET_CMDLINE", &ArmSemihosting::callGetCmdLine, 2, 2} },
     { 0x16, { "SYS_HEAPINFO", &ArmSemihosting::callHeapInfo, 1, 1} },
 
     // Exit is special and requires custom handling in aarch32.