arm: Avoid using solaris syntax for .section directive

Assembler from binutils 2.41 will rejects ([1], [2]) the following
syntax

.section "name", #alloc

for any other any target other than ELF SPARC. This means we can't use
it in the Arm code.

So switch to the GNU syntax

.section name [, "flags"[, @type]]

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=11601
[2] https://sourceware.org/binutils/docs-2.41/as.html#Section

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
[jgrall: Reword commit message]
Acked-by: Julien Grall <jgrall@amazon.com>

xen/arch/arm/arm32/proc-v7.S

@@ -29,7 +29,7 @@ brahma15mp_init:
         mcr   CP32(r0, ACTLR)
         mov   pc, lr
 
-        .section ".proc.info", #alloc
+        .section .proc.info, "a"
         .type __v7_ca15mp_proc_info, #object
 __v7_ca15mp_proc_info:
         .long 0x410FC0F0             /* Cortex-A15 */
@@ -38,7 +38,7 @@ __v7_ca15mp_proc_info:
         .long caxx_processor
         .size __v7_ca15mp_proc_info, . - __v7_ca15mp_proc_info
 
-        .section ".proc.info", #alloc
+        .section .proc.info, "a"
         .type __v7_ca7mp_proc_info, #object
 __v7_ca7mp_proc_info:
         .long 0x410FC070             /* Cortex-A7 */
@@ -47,7 +47,7 @@ __v7_ca7mp_proc_info:
         .long caxx_processor
         .size __v7_ca7mp_proc_info, . - __v7_ca7mp_proc_info
 
-        .section ".proc.info", #alloc
+        .section .proc.info, "a"
         .type __v7_brahma15mp_proc_info, #object
 __v7_brahma15mp_proc_info:
         .long 0x420F00F0             /* Broadcom Brahma-B15 */

xen/arch/arm/dtb.S

@@ -1,3 +1,3 @@
-        .section .dtb,#alloc
+        .section .dtb, "a"
         GLOBAL(_sdtb)
         .incbin CONFIG_DTB_FILE